Marimo moss ball propagation



Trendy, organic and alive, Marimo moss balls make an interesting conversation piece in your Edgewater apartment. These spherical green balls aren’t really a moss at all, but rather a ball of solid algae with nothing anchoring the center. Growing slowly, these aquatic plants are fun to care for, and because they need minimal sunlight, they make the ideal apartment plant. With the right care, your Marimo moss balls can easily thrive. Here are some tips to keep them green and healthy.

Because they grow underwater in cool lakes, Marimo needs light, but not direct sunlight. Direct sunlight will cause them to brown. Instead, use normal household light away from direct sun. If you have no window in the room where you are keeping the Marimo, use a full-spectrum bulb.

Every two weeks, change the water with regular tap water. To ensure it is the right temperature, allow it to sit at room temperature for 24 hours before changing. If you notice algae on the surface of the tank, clean it off when you change the water. Should you need to move your Marimo moss balls, you can take them out of the water for several days as long as you place them in a sealed container or bag so they don’t dry out completely.

Marimo moss balls naturally grow in a round shape. However, when you grow them at home, they may start to flatten. This is because they do not have the natural movement of the water that they would be subject to in nature. To keep the round shape, regularly agitate the water so that the Marimo balls move off of the bottom for a bit, then settle in a new location. This movement helps prevent unwanted flattening.

A container with water and Marimo moss balls will make your home distinctive. Whether you place them on your counter, an end table, your dresser or your desk, they are sure to draw attention, and they will mesmerize you at the same time. The sleek, trendy floor plans at Riello are the ideal setting for Marimo moss balls. Contact our office to see our available floor plans today.

Welcome to Marimo Moss Ball Central!

Marimo moss balls make beautiful decorations for fish tanks.

Last updated: 10/27/19. We keep this guide up to date so you get the most accurate information on the web.

(Found something inaccurate? Please let us know ASAP!)

Our site is dedicated to the care and knowledge of marimo moss balls. We are two long-time owners of moss balls and fish-keeping hobbyists, as well as aquarium geeks since College. When we were in college, we would sneak small nano aquariums into our dorm room and the marimos would often be the centerpiece of attraction when we would have “approved” guests over. People often ask questions like the following:

“What’s that green ball thing?”

“What’s that floating egg?”

“What is that thing?”

Even after college, we’re still big fish-keeping fans. I use marimo balls as a decorative item in many of my tanks. I have many aquariums dedicated to just moss balls and nothing else. We made this site because a lot of people seem to be asking questions about them, and are often misinformed.

We hope to clear up some of that confusion and answer your questions to keeping a healthy and happy moss ball. Most of the information here is based on our own experiences and lessons learned. This guide will save you a lot of headaches and confusion. Seriously.

The History of Marimos

Marimos are found at the bottom of shallow lakes.

Marimo moss balls originated in Japan. They were found to grow in shallow lakes. They’re popularly found in cold waters, such as their “home” lake- Lake Akan in Japan.

However, they’re also found native in Iceland and Estonia. They grow in shallow bodies on the lake floor up to depths of 2.5 meters. The circular shape, or should we say spherical shape, is caused by the water currents rolling, molding, and forming the ball.

The ball itself is actually made out of algae and that’s been rolled around in circles and formed into these moss balls. Most people know about these little green fuzzy balls simply as moss balls, and you’ve probably seen them in aquariums and fish tanks. They’re not exactly made of moss, as most people would assume.

Marimos are actually a type of algae that grows in partial light and eventually forms into a spherical ball under specific conditions. They are extremely popular in Japan, and now they’ve slowly gained popularity over here in the United States. They’re used in fish tanks, aquariums, display thanks, or even as low maintenance pets.

They require very little special care and offer an interesting experience. They have a spherical shape and are slightly bouncy. They can be kept in a variety of different habitats, including a bowl, vase, or fish tank. Some have had success with terrariums (water-less) tanks.

If you’re looking to purchase a moss ball, definitely do your research before you buy one. Marimos, in general, don’t have many requirements when it comes to care and habitat, but there are a few things you should take into account so you can ensure the health of your moss ball.

Choose the Proper Environment for your Moss Ball

Provide a proper housing environment. Don’t keep your marimo in direct sunlight. Although we mentioned earlier that they grow in sunlight, that doesn’t mean leave them in the sun all day. Algae naturally need light to grow, but a photocycle.

Leaving your Marimo in the sun for periods of time may actually have the exact opposite adverse effect and stunt its growth. In Japan, they actually appear on the bottom of lakes where it’s obviously dark.

Sunrays do reach the bottom, but it’s definitely partial sunlight and you should try to create the same effect environment within your marimo’s habitat.

Remember, it’s a living organism and responds to environmental cues. We suggest you do your research and also choose a place in your home before you actually make the purchase.

Marimo Balls with Other Fish, Shrimp, or Crayfish

Marimo moss balls are compatible with Betta fish.

If you plan to keep your moss balls in a habitat with other inverts or inhabitants, like crayfish or ghost shrimp, you need to take special precautions. These little creatures naturally love to eat, hide, and forage marimos.

You need to watch out for their habits and make sure they don’t cause too much of a disturbance for your moss balls. They will feed on them, but as long as there doesn’t appear to be any shrinkage of the moss, it’s fine. You may also want to house fish along with your moss balls. It really depends on the type of fish you want to co-inhabit with.

Goldfish are usually a popular choice, however, they don’t make a good tank mate for a moss ball because they love to eat algae. Pleco fish also have the same problem. If you want to house your algae ball with a fish, you should go for a non-aggressive fish that doesn’t need to be housed in schools, such as a Betta fish.

The variety of patterns a Betta fish has can easily match or contrast with the yellow-green or dark-green coloration of moss ball. Betta fish also make great tank-mates because they don’t generally feed on algae, so they will coexist with planted tanks, moss balls, or other aquarium decorations you may have in your fish tank. We definitely recommend that you choose a non-aggressive fish species if you must have fish within the same tank.

Marimos and Saltwater Tanks

That covers freshwater tanks, however many you probably want to keep marimo moss balls in saltwater tanks. This actually can be done, believe it or not. However, it depends on the type of water. Brackish water is a proper housing environment and marimo moss balls thrive in waters with salinity up to about 1.015.

That’s about low-to-mid brackish water. In fact, adding salt to your aquarium is a recommended solution when your marimo moss ball is morphing to a brown shade. They actually do grow in salty water conditions in Japan. In fact, the thickest marimos were found to be where dense salty water from multiple natural springs runs together to join into a lake.

Right at the opening where these springs ran into the lake, the largest algae concentrations within a moss ball were found. That’s because these springs bring in nutrients and salt from runoff sources on the land and bring it straight into the lake.

So, if you want to use your moss ball in a saltwater tank, it’s perfectly fine to do so. Just make sure to check the salinity level and make sure it’s not too high. If you have a freshwater tank and you now want to convert to a saltwater tank, make sure that all the inhabitants in the tank can handle the additional salinity.

Generally, freshwater and saltwater tanks don’t mix. If you have freshwater fish in freshwater habitats, you don’t add saltwater. However, if you are housing the marimo by itself along with some other plants or inhabitants where salt content doesn’t affect them, you may add a few doses of salt and bring up the salinity to grow bigger moss balls.

We suggest using a salinity meter (also known as a hydrometer), which is readily available at any pet store, to make sure you are within the proper range for optimal care of your last ball. We use one made by Instant Ocean that you can check out on Amazon here.

The reason for this is because we also use their sea salt (as you’ll see next), so it makes sense to get them both from the same brand (for calibration purposes).

Some readers have contacted us about what exact salt we use and in what dose. We have a lot of marimos to care for, so we buy Instant Ocean Reef Crystals salt in bulk. It’s available for 10-gallon mixes up to 200-gallons. You can check it out on Amazon here.

It’s used for marine aquariums and is safe for marimos in small doses. Depending on the housing conditions of the ball and other inhabitants, we alter the amount of salt used.

Each marimo that’s housed by itself or with other marimos (that means no other fish or inverts) has a pinch salt added (like a literal pinch). We try to get the salinity to just around 1.010-10.020sg and leave it there. If the ball starts losing color, lower the salinity by doing a water change (partial) or adding distilled water. If you can add salt and the ball doesn’t turn greener, that’s the sweet spot for faster growth speeds.

Keep the container open to fresh air

A common question we get from readers is whether or not they can store these algae balls in a closed container. By this, they mean things like jars with lids, bottles with caps or corks, or small mason jars with sealed tops.

Like any other plant, these balls need a constant supply of fresh air. When light hits the container, photosynthesis takes place, which requires a constant supply of fresh air. They also release oxygen as a product of the reaction, which needs somewhere to diffuse to. If the container is closed, the marimos will use up all the available air and simply convert it all to oxygen and by-products from the reaction.

Think about them like any other plant. Would you put a sunflower or daisy in a sealed mason jar? Probably not.

Marimos need the same care. If kept in a sealed container, they’ll turn brown quickly when all the available elements in the jar are used up. Don’t let this happen.

Change the Water

Slight browning means you need to clean your marimo.

Make sure you change the water. As with any fish, you should already know to do partial water changes about once a week or full water changes about once a month. When you do these changes you’re supposed to clean out the tank and remove either a portion or all of the water, depending on if it’s a partial or full change.

The new water that’s added to replace the removed water should be treated with a liquid dechlorinator and water purifier. Our favorite water dechlor is Prime by Seachem. It’s one of the top dogs in the hobbyist world and one of the most respected brands. Please read up on how to do water changes if you are new to this or if any of this sounds unfamiliar to you. Getting back to my marimos, whether you keep it in a tank by itself or with other inhabitants, water changes are always important.

We recommend doing partial water changes, removing and replacing about 25% of the water, at least once a week. If you are using tap water, make sure you treat it using a water treatment solution which is available at any commercial pet store.

Although there are reports that you may use regular tap water, different cities and states have different water hardness.It’s much easier to just buy a tap water treatment solution and treat your tap water and use that as prepared water for your partial water change.

However, if you know you live in an area where the water hardness is very low, You may wish to use tap water and that should be fine. This is only if you just have a marimo by itself. But if you have fish, you must use a water purifier. A marimo by itself can be treated with tap water just fine, assuming you have low water hardness, but fish will always need treated water.

Cleaning your Marimo

Marimos require cleaning. You should dive in with your hand and pick up your moss ball every other week and gently inspect it to make sure it’s still clean. I think of it like a dog.

They both need cleaning over time depending on how the tank conditions are. If your moss balls are housed by themselves, they won’t dirty too often. However, if you have other inhabitants in the tank and they leave waste, eating food, or dug up sand, you’ll need to inspect your moss balls more often. When you do the inspection simply pick it up and inspect all sides of it. You’ll instantly know if it’s dirty because it’ll turn brown or gray.

Washing it is easy. Simply squish it multiple times in a container with some clean water. You can also swish it back and forth within the same container, but make sure you have a firm grip on it or else you may break it apart. Afterward, or if you did happen to break it, you can roll it in your palms and sort of mold it into a spherical shape again. Gently roll it around to prevent it from falling apart, but be sure to do this very gently. This will restore the round shape and help the algae strands latch onto each other for a firmer ball.

You’d be surprised to know that in nature, marimo moss balls get rolled around naturally. By sitting at the bottom of the lake, the water current actually helps push them and roll them along the bottom of the lake bed. So, that’s how they keep a rounded shape and structural integrity to stay nice and firm.

Of course, this doesn’t happen in your fish tank so you’ll have to act as a water current and roll them up with their hands. Just be gentle and careful. If you happen to break off a piece and it doesn’t look like it can be reattached you can roll that one up as a separate entity by itself. We think this is a pretty interesting phenomenon and only adds Zen-like qualities to these creatures.

Watch the Temperature – Keep it Cold

Keep the water as cold as possible. It mimics their natural environment.

Keep an eye on the temperature. Marimos prefer colder temperatures. In the wild, marimos only appear in cold waters around Iceland in Northern Japan. If you have an aquarium heater or live in an area where it’s naturally hot, you may have to either get an aquarium chiller or move the marimo’s tank to a cooler area.

If you have other fish in the tank that require a certain temperature that’s warmer, it may not be a good idea to have them with the balls since they have different temperature requirements. However, if you’re housing the ball by itself, it should be fine to simply move the habitat and a cooler spot. It’s actually advisable to place the entire habitat in your refrigerator, assuming it fits, during the hotter months. The temperature that you need to watch out for is 25 degrees Celsius.

Try to keep the temperature between 17 – 23 degrees Celsius. If the temperature goes higher, you have to move it to a cooler area. If you are housing it by itself, you can also add some ice cubes to the water to cool it down if it’s just a temporary hot day. If you live in an area where it’s consoling hot, chances are you’re running the air conditioning. Consider placing the habitat near and air conditioning outlet vent where there will be a constant supply of cool air hitting the tank.

This is why it’s important to do your research in the very beginning and see if you are going to have the right setup and to decide hosing marimos by themselves or with other inhabitants. They all need to have the same temperature compatibility, so that’s why you need to look out for these important considerations.

How to Care for Marimo Moss Balls

Roll your balls. You need to roll your moss ball every other week or so to make sure all sides of it receive light evenly. If you only allow one side to receive that the other side won’t grow and will probably start turning brown. If this happens to you, simply move it so that all sides of the sphere receive some degree of light.

We suggest that you don’t place other moss balls close to it or other decorations in the tank because they may disturb the sunlight that one ball may receive. If that light is coming from directly above, then you can place as many marimos next to each other as you desire.

However, if the light is coming in at an angle, one ball may block the sunlight from being received onto another one. Just be wary of each moss balls’ surroundings and what direction the light is coming from. It’s vital that you try to make sure each ball receives light from all directions and equal an ounce of it at that.

Is your Marimo turning Brown, Gray, White, or Black?

Marimo moss balls are easy to care for and low-maintenance.

Keep your marimo healthy.

They’re generally pretty hardy and can withstand a range of temperatures, water conditions, and inhabitants. They can be fed on, they can be grown in cold water, they can be torn apart, and they can be grown in saltwater. They are definitely tough.

However, there are some conditions that require attention and care. You’ll notice this when your marimo turns to a different color.

My marimo is turning brown/gray:

When they change colors to a brown or grayish color, they often need to be cleaned. If your moss balls turns gray or brown, it’s fine- it’s nothing to worry about. Simply give your marimo a nice shower and it should be fine, use the instructions above to clean your moss ball.

My marimo is turning white, or has a white layer:

If it turns white or has a whitish tent, you may have a problem. It probably means that there’s too much sunlight. Move your moss ball to a darker location.

My marimo feels slippery or slimy:

If your moss ball is slimy or slippery, there may be a type of invading algae growing around it. Although moss balls themselves are made of algae, there are foreign invading algae that like to feed on your marimo’s algae. These “bad” algae basically form a seal around the ball and choke it. The solution is to simply wash off the outer layer slowly, and often.

If the layer is visible and easily tangible, use tweezers to pick it off. We suggest you do this early and often until you see no more “bad” algae growth. Increasing the salt concentration of your water may help too. Do both of these tactics and your moss ball with being green and happy again- without the slimy texture.

My marimo is brown even after cleaning it:

If your marimo is brown even after multiple washing attempts, this is a sign that it’s very dirty. We suggest giving it a bath instead of a shower. Clean it thoroughly and swish it around gently in a tub of saltwater. Use a tweezer to remove the browned parts.

My marimo is brown on one side:

If only one side of the Marina has turned brown, it’s because it probably didn’t receive sunlight for a long period of time. Just simply rotate the ball and turn it around with the brown side facing the light. When it becomes green again, simply roll it and roll it often so all sides receive equal lighting.

My marimo broke or I ripped it apart by accident:

If your moss ball is falling apart, you can pick up the last part and roll it into a ball by itself. Be sure to give it a cleanse and reform it with your palms. Do this for both the original ball and then newly-formed one that you just made. Inspect the color and make sure it doesn’t turn brown. If it does, it needs sunlight. Give all parts equal sunlight and also wash them often. The new ball should turn bright-green after going through a slightly darker-green phase. You’ll now have 2 moss balls from 1.

My marimo is turning black:

If your marimo turns black, it’s probably due to neglect and improper care. It could also be due to hostile algae that hasn’t been treated or it has simply been neglected for too long and regular maintenance hasn’t been practiced. Immediately remove the black parts and wash the ball. Reform it easy multiple times a week until it becomes green again.

If it changes to any other color, refer to this guide and treat it accordingly. Chances are, you are new ball will be much smaller than it was before, but at least it will survive and begin growing again. Be sure to increase the salinity of the tank and watch for color changes. Treat changes immediately using this guide.

How to Choose a Healthy Moss Ball

Your moss ball should be full and green!

Choosing a healthy marimo can be difficult, depending on where you buy your moss ball. You need to be on the lookout to make sure you’re choosing a healthy and genuine Marimo. Many stores actually carry fake moss balls because they look just like the real thing- whether intentional or not.

So you need to be sure that you choose the right ball. We put together a few pointers to help you choose a real one and a few other points to consider when you’re staring at these moss balls in the tank.

The first thing you should do is to ask the store owner to let you handle it. Feel the shape of the ball by rolling it between your palms. You should be able to easily mold it and shape it into whatever you want. If it’s ovular, you should be able to shape it into a more spherical shape without too much force. If it stays in a non-moldable shape, it’s probably a fake.

You should also be able to pick it apart. The store owner probably won’t let you do this, but you should be able to get a feel for it just by feeling the texture of it. It should feel loose and easily broken apart if you were to attempt it. It should be fragile yet feel like it’s stringy at the same time. A better way to put it would be fragile and firm. We suggest that you ask the store owner before you attempt anything too dangerous.

You should be able to feel the texture of it with your fingers and graze over the moss. It should feel bumpy and crater-like. A real marimo ball has a whole bunch of craters, strength, hard parts, soft parts, and bumps all over the surface. If it’s too smooth or too perfect, it’s probably fake.

You want to find imperfections all over the surface, which is perfect. Imperfect makes perfect. We suggest that you don’t only feel the surface, but also dig in to see what’s below it. It should all be the same material and your fingers should easily penetrate through the surface.

Fake moss balls usually have a plastic ball, such as a ping pong ball, in the center and are covered with fake moss. You may be able to see this by the center simply looking through the moss. If you see any weird colors from within, it’s probably a fake. Of course, this doesn’t work with giant moss balls since the moss will be too dense for you to see to the core of it. However, for mini ones, you may be able to see the center through the cracks.

If your pet store carries balls in plastic packaging or some kind of container, it’s probably a fake. A real moss ball should be kept in a planted tank in a complete setup. But, this is not always the case, as they can be transported and sold in some kind of packaging, including real ones. This is just another thing to look out for.

When you inspect the ball, give it a little squish. You should easily have it conform to the shape of your fingers and you should feel like it can be molded into any shape you desire as if it were modeling clay.

Although we don’t suggest that you do this in front of the store owner, make sure you do it at least a little bit just to get a feel for it. If it feels hard and unmovable, it’s probably fake because it has a hard center. However, if it’s a real moss ball, you should feel it being squishy since there’s nothing solid at the center. When you squish it, water may drip out and about like a sponge, so make sure you do it over a fish tank, or else that store owner is going to really not be happy.

Where to Buy a Marimo Moss Ball

Buy your moss ball from a reputable source.

Most people will buy them from pet stores and major chain retailers but are completely unaware of the high amount of fakes that exists. Store owners don’t know as well. Or they may completely know about it but expect you not to know about it. That’s why you need to use those pointers up above to make sure you pick out a healthy ball.

Generally, moss balls are priced based on their size. If the deal seems too good to be true, it’s probably because they’re fake. Small moss balls that are about 1” across generally range from $1-1.50 a piece.

Larger ones that range from 2” inches can go $4-5 a piece. Giant marimos can go anywhere from 2.5-3” and can be up to $13 a piece. If the price seems too good to be true, it probably is.

There is a bad practice of sellers, especially online, that basically take one moss ball and rip it into pieces and reform them into many mini moss balls. They state that they’re all original and not appendages from a torn apart giant ball.

This basically gets them many moss balls to sell for the price of one. Sadly, this is hard to detect if you’re buying online. If you’re in the store you can use the pointers we gave you above to easily find out if the owner seller did this.

But if you’re buying them online, it’s going to be very difficult to tell if the seller has any shady practices. In fact, if you’re going to buy balls online, you can’t really practice any of the tips we give you above rather than simply looking at the pictures, however, this will only do so much as you can’t really do any inspection by just looking at pictures and because pictures can easily be fixed. They could have easily stolen them from someone else or just simply downloaded random images of perfect moss balls from the internet.

We’ve had a lot of people ask us questions like why their moss ball isn’t growing or why it’s changing color and we often ask where they bought it from. The majority of the time, it’s the internet. There a lot of sellers online that sell these for cheap and because of bad practice.

They can sell them for so cheap because they’re either fake or simply torn apart into multiple moss balls. You need to watch and steer clear from these sellers and make sure you do your research before you make any purchases online. In person, it’s a lot easier to identify the fakes so that’s what we would suggest for you to do when you make your purchase.

Our Online Marimo Store

Marimo moss balls craft a zen-like environment.

Since this is a topic that we got a lot of questions on, we have decided to sell own moss balls online. You can check out at our marimo shop here.

We’ve decided to work with suppliers to import directly from the lakes of Taiwan, Japan, and the Far East- directly from the source. We certify that all our moss balls are 100% authentic and native. This will be a surefire way to guarantee you’re buying from a trusted source. The marimos we sell are real, healthy, and authentic.

We hope this guide answers a lot of your questions regarding these fuzzy algae balls. They’re a great species to play with and escape with. And they make a great addition to fish tanks, and they thrive and do well on their own as well. We often see them as a centerpiece for many end tables and desktops. You can add them to a planted tank or have them in their own aquarium.

If you paid attention to this guide, you can easily take care of your balls because you would see that the care isn’t that intensive. They’re low-maintenance species and make a great addition to brighten up and add some kind of entertainment value to whatever fish tank or aquarium or another centerpiece you decide to add them to.

Moss balls can be used on their own as a pretty display.

We think the recent break out in popularity is due to chain pet stores carrying the product now and people becoming aware of them. People walk into a pet store become intrigued by the floating green fuzzy ball and wonder what it is. People that do research and end up in places like where you are right now.

We wrote this guide to help you decide to make the purchase and get yourself a healthy set of moss balls. Or if you’re new to the hobby, maybe you just want to order one for now. Take care of it and it will offer you zen-like qualities as it really works of art for you to admire daily.

I, Anthony, and Rob hope that you can take pleasure in the ownership of these fuzzy little as much as we do. Be sure to check back often as we update our website with care guides, new products, marimo news, and other marimo related stuff every so often. We’re still a new site so bookmark us (CTRL + D)!

Please consider sharing this article

If you’ve learned something from this article, please consider sharing it.

From one marimo lover to another, it really helps out and educates people before they make their purchase, and helps them take proper care of their moss ball as well.

You can use the social buttons below or at the top of this article.

Ready to buy your marimo moss ball?

If you have any questions, you can send us a message. We reply as fast as we can to help you out.

If you’re ready to purchase, please check out our shop, we sell marimos by trusted vendors that we’ve personally verified, or that we’ve sourced ourselves.

Have you ever seen funky green balls of moss in an aquarium? Something that is gaining popularity amongst aquarists both beginner and advanced is marimo moss balls!

This article is going to look at why these moss balls are becoming so popular and why it could be a great idea having a marimo moss ball in your betta fish tank. Starting with looking at what is a marimo moss ball, the advantages of having them in your tank, marimo moss ball care and also how to add them to your tank.

Check it our on Amazon.

What is a Marimo moss ball

Marimo is a type of moss ball that mainly grows in the northern hemisphere. Marimo is its Japanese name; it’s also is known as a Cladophora ball.

Like most underwater plants, it photosynthesizes, it takes in carbon dioxide and releases oxygen as well as consuming nitrates. The moss balls are nearly indestructible – no amount of nudging from your curious fishes will bring these down!

Despite their name, they are in fact not related to moss at all; they are more closely related to algae. The name “Marimo” was coined by the Japanese botanist Takiya Kawakami, a combination of “Mari”, meaning bouncy play ball, and “Mo”, a general term for water plants.

The benefits of a marimo ball

The Marimo moss ball brings with it a variety of benefits to your aquarium:

1. Aesthetics: First of all, the marimo moss balls look great! Looking right at home with other plants in a home aquarium, and provide a very clean yet natural feel to their environment.

Even on their own, moss balls are a nice addition to any themed tank. Our beta fish have always approved the introduction of a moss ball to their home!

2. Reducing Nitrates: Nitrates are produced by fish during the course of their life. The level is usually harmless to them, but this is why it is important to do regular water changes.

However, having a Marimo moss ball in the tank can help reduce the number of nitrates at all times. They feed on these nitrates to survive and grow.

3. Phosphates and particulates: The Moss balls not only provide an active defense against nitrate levels but also a passive one. Their spongy texture allows them to act as a filter, removing phosphates and particulates from the tank, which algae would use to feed and grow on things such as aquarium plants, cutting off sunlight or even on the glass walls themselves.

4. Oxygen: Just like humans fish breath oxygen – fish take their oxygen from the water using their gills (A side fact – Did you know betta fish are one of very few fish that can even take oxygen from above the water’s surface – but that’s another blog post).

As fish breathe they take (and use up) the oxygen in the water and replace it with carbon dioxide. Well guess what? That’s right marimo moss balls take in this waste carbon dioxide and replace it with oxygen. Your fish will be pleased!

5. They are cheap! The price of a set of four giant Marimo balls is as low as ~$10.

6. Easy! Marimo moss balls are so easy to look after. Once you add them to your tank they require no attention!

Marimo Moss Ball Care

Taking care of your marimo moss ball is easy! In most cases you add them to your tank and they will then become part of your aquarium’s aesthetics. Providing both style and helping keep your tank water clean.

However, if you wish for the healthiest marimo moss ball here are a few tips for you…


Marimo balls require low to medium levels of indirect light – too much sunlight can cause them to brown.

If this begins to happen with your moss ball, the best solution is to simply move the ball into an area of the tank with lower light levels.

Water Changes

Take the time during water changes to agitate the moss ball slightly or simply place it on another side. This is to make sure it gets an even amount of light all around and also to retain its round shape.


Floating is a regular sight for moss balls. Usually, it indicates a trapped air bubble inside, this can be fixed by gently squeezing the ball.

Usually floating happens when you first add a marimo moss ball to the tank. It will usually sink within a few days of being added to a tank.

Don’t worry if your moss ball floats when you first add it to the tank, why not leave it there for your betta fish to investigate?

How to know if your moss ball is dead

A dead moss ball can be identified as it will be mostly or completely brown, which indicates it is either completely or mostly unrecoverable. At this point, the moss ball can simply be removed as regular garden/organic waste. There is no way to rejuvenate them at this stage

How To Add A Marimo Moss Ball To Your Aquarium

First remove the moss balls from their packaging and inspect them for any brown or miscoloring.

You should clean/rinse them before you add them to your tank. Who knows the type of water they have been sitting in! You do not want any of this in your tank.

Use a jug or mixing bowl with some water from your aquarium. Add the marimo moss balls to this water and rinse and squeeze them to remove any dirt.

(Now you can see why we recommend to rinse and clean them first! This dirty water would have been in your tank.)

Next, you can add them to the tank, just drop them into your tank gently.

Some may float for a while. This isn’t a problem (as we said before, feel free to leave them floating for your betta fish to investigate).

Move them into place. They look great with other plants too!

Did you know you can get mini marimo moss balls?

Subscribe today and receive a FREE Betta Fish Care for Beginners eBook

Are you a little betta fish crazy? Join over 7000 members and subscribe to our email newsletters for betta fish care tips, betta fish fun and a free betta fish care book.

Thank you for subscribing.
Check your inbox for instructions

Oops… Something went wrong.

No spam. No 3rd parties. We respect your privacy and take protecting it seriously

What is Marimo?

Do you know Marimo? Roundish, green, and mossy—this unique indoor plant is full of personality! Marimo moss balls are equally strange and charming, allowing them to grow in popularity as interesting house plants. Aquascapers and aquarium fanatics are no strangers to these fuzzy algae balls as they are both decor and filtration for fish tanks. Marimo moss balls are increasingly found at garden centers and online for use in home water gardens of all sizes.

Marimo is the Japanese word for “ball seaweed,” which should give you the hint that, despite the common moniker Marimo Moss Ball, it is not moss at all. It is a type of green algae, Aegagropila linnaei, usually found in Australia, Estonia, Scotland, Iceland, and Japan rolling around at the bottom of freshwater lakes. Marimos are solid algae, radiating from the center and weaving themselves into a dense ball that is incredibly slow growing. Marimos grow only a few centimeters a year, so purchase them at a size you like and they will provide low-maintenance enjoyment for many years to come.

Caring for Marimo Moss Balls

Caring for a Marimo moss ball is easy, with no daily effort and almost no maintenance beyond changing the water. A Marimo moss ball is a great first plant for children and self-proclaimed “Black Thumbs.”


Marimos are aquatic plants and, therefore, they need to be submerged in water to survive. The water requires no special care like distilling, adding chemicals, or boiling. Tap water is just fine in most areas unless your water is undrinkable from the tap.

Keep the water at room temperature and change it every two weeks. Frankly, I probably change the water every four to six weeks and my Marimos are happy as clams. The bowl gets a bit slimy after that time and starts to look cloudy, so I take five minutes to wash it and get back to enjoying these low-maintenance plants.

How to Clean Your Marimo Moss Balls

  • First, remove them from the water and set them in a bowl.
  • Wash the bowl, rocks, and any decorative items with gentle dish soap and warm water. Use a sponge or nail brush to scrub the film off the inside of the bowl.
  • Rinse the Marimos under tepid, running water by gently squeezing out the water and allowing them to fill again.
  • Fill the bowl back up with water and add the Marimos. If you have squeezed out too much water they will float to the top. Eventually, they will saturate with water again and sink to the bottom.

Tip: Don’t squeeze them into the clean water if you want them to float. The water removed will make the bowl cloudy, and you will have to change it again.

Get the Lighting Right

Marimos usually grow on the floor of lakes, so they do not want direct sunlight. Normal household lighting is just fine. Keep them safe from bright light and they will stay healthy for years.

Propagating Marimo Moss Balls

That nice, round shape comes from rolling around on the bottom of a lake when they are in nature. The Marimo that you’ll adopt is most likely captive bred. Breeders will divide up larger balls into many small ones by pulling off chunks and rolling those into a ball shape. Many of the “nano” balls that are sold are made this way. It will take some time for the algae to restructure and grow back into a ball shape with threads radiating from the center. In the meantime, they look pretty much the same and are not harmed.

If you have a large or misshapen Marimo, you can divide it and roll it into balls. Remove the balls from the water occasionally and roll them gently between your palms. Eventually, they will look like velvety round moss balls.

Beware of Fake Marimo Moss Balls

A real Marimo moss ball will be solid algae throughout, with the growth pattern radiating from the center outwards. It will tear easily if you try, but should not simply fall apart in water.

As with all plants, only purchase a Marimo from trusted suppliers. There are many fake Marimos out there, from Styrofoam balls with artificial moss glued on to hair algae rolled into balls. Ask the supplier if the Marimo they are selling is Aegagropila linnaei, and where they got their supply. And be sure to only make purchases from suppliers who stand by their products so that you can return it if you realize that it is a fake.

Designing with Marimo Moss Balls

If you are looking for a fun garden therapy project that has almost no care requirements, then use marimos to create a modern living water garden! Here is a simple Marimo moss ball water garden that you can make in just a few minutes.


  • Marimo Moss Balls
  • Glass Fishbowl or Vase
  • Aquarium pebbles
  • Branches or coral
  • Ceramic fish, shells, or other decorative elements

Make it!

First add decorative pebbles to a clean glass vase or fishbowl. The wider the vase, the larger the moss balls will look. The water and glass easily distorts the size of what is inside, so choose decorative elements and moss balls that are smaller than you think you need.

Fill the bowl with tepid water.

Add any decorative elements like branches, coral, ceramic fish, or seashells to the bowl. You could even add a miniature garden scene under water.

Now rinse the Marimos under running water but squeezing them gently. Roll them between your palms to keep a nice ball shape and add them to the bowl.

Love Gardening Indoors? So do I! Here are Some More Ideas:

  • Crafting with Air Plants and Wire
  • What Kind of Tillandsia do I Have? Identify and Care for Common Air Plant Varieties
  • Indoor Plant Care: How to Grow Tropical Plants in Geometric Terrariums
  • My Indoor Herb Growing Schedule Throughout the Year
  • Bring on Spring! How to Force Spring Bulbs Indoors
  • The Most Beautiful Flowering Houseplants

How do I take care of my Moss Ball Pets™?

Moss Ball Pets™ require water and very minimal light source to survive. It does not require feeding as it performs photosynthesis just like a plant.

What type of light source do I use?

Any source of natural or artificial light is good enough for your Moss Ball Pets™ to live in a healthy and green condition.

Do I need to change the water? What type of water should I use?

Tap water is good enough. It is recommended to change the water your Moss Ball Pets™ live in once a week or every two weeks.

What should I do when changing water?

You may gently squeeze your Moss Ball Pets™ to flush out any dirt trapped in it. You may also gently rolls your Moss Ball Pets™ back and forth on your palm to help them retain their round shape. Moss Ball Pets™ are living things and they need your love!

Can I have fish or shrimp with my Moss Ball Pets™?

Yes, definitely.

How long can my Moss Ball Pets™ live?

The world’s largest Marimo is about 95cm in diameter. Marimo are able to grow about 5mm per year. Thus, the World Largest Marimo today are over 200 years old!

Why is my Moss Ball Pet™ changing color?

Change in color from green to brownish shows that your Moss Ball Pet™ is sick! Please wash your Moss Ball Pet™ under running water and add some salt (5% of your water volume) into your Moss Ball Pet™ container or tank for about a week or two.

How long can my Moss Ball Pet™ last without water?

In ideal conditions, Moss Ball Pets™ can live for one month without water. It is not recommended to keep your Moss Ball Pets™ out of water for any extended period of time.

Why do Moss Ball Pets™ float and sink?

More often, Moss Ball Pets™ will sink in water. However, when Marimos perform photosynthesis, the oxygen bubbles generated by the Marimo can make the Moss Ball Pets™ float up to the surface of the water. Don’t be alarmed as that is normal Marimo behavior and indicates a healthy pet!

Will Moss Ball Pets™ reproduce or split into two?

Yes, Marimo will reproduce when they are kept in a large pool of water. However, it is not recommend to split up your Moss Ball Pets™. Very often you may damage it and it can cause it to die. If you are lucky your Moss Ball Pets™ would reproduce and you would see a bump growing on them. Congratulations for that is your new baby Moss Ball Pet™!

How can I help my Moss Ball Pets™ grow faster?

You can help by lowering the temperature and improving the water quality.

Would high temperature affect my Moss Ball Pets™?

Yes, direct sunlight would hurt your Moss Ball Pets™! If you wish, you can leave your pet with water in your fridge for 24 hours to give it a nice cool environment to grow.

Can Moss Ball Pets™ survive in a fully sealed/covered bottle?

Yes, Moss Ball Pets™ can survive in fully sealed/covered bottles. In fact closed bottles can keep out the dust and other pests that may harm your pet!

What Is A Marimo Moss Ball – Learn How To Grow Moss Balls

What is a Marimo moss ball? “Marimo” is a Japanese word that means “ball algae,” and Marimo moss balls are exactly that – tangled balls of solid green algae. You can easily learn how to grow moss balls. Marimo moss ball care is surprisingly simple and watching them grow is a lot of fun. Read on to learn more.

Marimo Moss Ball Information

The botanic name for these fascinating green balls is Cladophora aegagropila, which explains why the balls are often known as Cladophora balls. “Moss” ball is a misnomer, as Marimo moss balls consist entirely of algae – not moss.

In their natural habitat, Marimo moss balls can eventually reach diameters of 8 to 12 inches (20-30 cm.), although your home-grown Marimo moss ball probably won’t be quite this large – or maybe they will! Moss balls can live for a century or more, but they grow slowly.

Growing Moss Balls

Marimo moss balls aren’t too difficult to find. You may not see them at regular plant stores, but they are often carried by businesses that specialize in aquatic plants or freshwater fish.

Drop the baby moss balls into a container filled with warm, clean water, where they may float or sink to the bottom. Temperature of the water should be 72-78 F. (22-25 C.). You don’t need a large container to start, as long as the Marimo moss balls aren’t crowded.

Marimo moss ball care isn’t too difficult either. Place the container in low to moderate light. Bright, direct light can cause the moss balls to turn brown. Normal household light is fine, but if the room is dark, place the container near a grow light or full spectrum bulb.

Change the water every couple of weeks, and more often during the summer when water evaporates quickly. Regular tap water is fine, but let the water sit out for a full 24 hours first. Agitate the water occasionally so the moss balls aren’t always resting on the same side. The motion will encourage round, even growth.

Scrub the tank if you notice algae growing on the surface. If debris builds up on the moss ball, remove it from the tank and swish it around in a bowl of aquarium water. Squeeze gently to push out old water.

Sometimes we just need to add a natural feel to the space somehow, and I think that there’s nothing better than water features and potted plants. If we take water bodies indoors, aquariums and water gardens are the choice. While not many of us are ready to take full care of living fish and aren’t ready for the costs, there’s an easier natural way to have a living aquarium at home – go Marimo!

Marimo is the Japanese word for “ball seaweed”, which should give you the hint that, despite the common moniker Marimo Moss Ball, it is not moss at all. It is a type of green algae, Aegagropila linnaei, usually found in Australia, Estonia, Scotland, Iceland, and Japan rolling around at the bottom of freshwater lakes. Marimos are solid algae, radiating from the center and weaving themselves into a dense ball that is incredibly slow growing. Marimos grow only a few centimeters a year, so purchase them at a size you like and they will provide low-maintenance enjoyment for many years to come. Now let’s take a look how to style such a piece.

Here’s a take on how to decorate a very simple glass terrarium with funny figurines and Marimo balls. If you’re not into dirt or you’re not big on gardening, no worries. This is one of the easier types of terrariums to start with, and I’d say it’s probably the best choice for any beginner looking to grow something green without having to worry too much about taking care of it. Japanese Marimo moss balls are one of the easiest things to maintain and, dare I say, the cutest little things nature has ever come up with, second to puppies and kittens. The Marimo ball itself acts as a filter that picks up nitrates and cleans the water.

DIY funny Marimo moass ball aquarium for kids (via

Ready to DIY & say hello to your new friend? It’s fluffy and not only are Marimo fun to look at, neat to explore/handle, it’s also one of the easiest plants to take care of. In the right conditions live to be 100 years old, a true friend for life, so let’s roll! These decorative aquatic plant pets are so cute and it’s really fun to observe these mysterious, happy and fuzzy moss balls.

cool DIY testing tube Marimo ball terrarium (via

This may be the easiest DIY indoor water garden you could ever plant. Moss balls are not fussy in any way, so you can really use your imagination in decorating the aquarium. You can use different approaches based on what you want your indoor water garden to look like. Many people create a more “seashore” type scene, and this can be pretty too if you want a more coastal feel.

DIY coastal-inspired Marimo ball terrarium (via

If you are looking for a fun garden therapy project that has almost no care requirements, then use marimos to create a modern living water garden! Here is a simple Marimo moss ball water garden that you can make in just a few minutes. Though Marimo balls are super easy to take care of, there are also fake Marimos out there, from Styrofoam balls with artificial moss glued on to hair algae rolled into balls – such Marimo will make your aquarium even more durable.

DIY easy water garden with Marimo balls (via

Native to Japan, Marimo moss balls are a filamentous form of algae found at the bottom of fresh water lakes and rivers. Marimos form a velvet-like nearly perfect sphere of green with a moss-type appearance. Marimo moss balls grow by absorbing nitrates, phosphates, and other organic waste from the water. Consuming animal waste in the water makes them perfect companions for fish. This tutorial will tell you how to make both fish and non-fish aquariums.

DIY Marimo moss ball terrarium (via

Time to make a very elegant and chic Marimo aquarium! Here’s a DIY instruction on how to make your own pretty mini aquarium or water terrarium containing Marimo moss ball and your own collected beach treasures – such a decoration will remind of your beach holidays.

DIY qater garden reminding of your beach holidays (via

Marimo Moss Balls are one of our very favorite plant discoveries of the last few years. Marimo are equal parts bizarre and beautiful, and Marimo moss ball care is very easy.

Marimo, a Japanese word which literally translates to “seaweed ball” are not moss at all – they’re actually a rare form of spherical algae. There’s no central stone or kernel inside the sphere – it’s solid algae, radiating from the center, growing radially outward at the snail’s pace of just 5mm per year. But in their natural habitats – few fresh water lakes in Japan, Estonia, Iceland, Scotland and Australia – they’ve been known to grow to between 8 and 12 inches in diameter!

Another reason to love Marimo moss balls is beautiful lore that surround these mysterious aquatics. Legend tells of two lovers who desired nothing more than to be together. When their love was forbidden, they fell into the water, and their hearts became Marimo balls. Marimo are said to bring your heart’s desire to both giver and receiver.

And of course, we love Marimo because they live forever. Well, not forever, but easily 100+ years. For this reason, we often joke that Marimo make wonderful family heirlooms.

Marimo moss ball care is quite simple. Here are a few guidelines.


Keep your Marimo where they will receive llow to medium indirect light. You must protect marimo from the direct rays of the sun, as Marimo can easily turn brown if they are getting direct light! Also keep in mind that direct sun will be intensified by glass marimo enclosures which can heat water quite quickly. Remember – these guys are native to cool lakes, and should be kept cool.

Marimo are well adapted to low light spaces and can photosynthesize in normal household light. If your space has no window, keep marimo close to a fluorescent or full-spectrum bulb.

Changing the Water

Change water once every two weeks using regular tap water (for best results, allow water to sit out for 24 hours prior to changing the water). You’ll need to change the water more often in summer, as it will heat and evaporate more quickly. Clean your marimo enclosure with a brush if algae begins to grow on tank surface.


If your marimo turn brown, make sure they’re moved to a cooler location with less direct light. They may recover and turn green again on their own. If not, you may add a tiny amount of aquarium ocean salt.

Why are my Marimo Balls Floating?

More than likely, your Marimo balls have an air bubble trapped inside that is causing them to float! Gently squeeze your marimo balls to pop the air bubble. Generally, Marimo will sink to the bottom of their tank within 1-2 days of being added to an enclosure.

Can Marimo Survive Outside of Water?

Yes! Marimo moss balls can survive without water if kept in plastic or a closed jar for several days, as long as they aren’t allowed to fully dry out. Plastic bags are the easiest way to travel with Marimo moss.

Keeping Marimo Shape Round

In their natural habitats, the waves and currents of the lakes gently rotate and roll the Marimo balls along the floor of the lake.

To ensure that Marimo stay keep their round form and don’t flatten out, you’ll want to gently agitate the water in your Marimo enclosure, with the goal that when your Marimo balls settle back to the bottom, they rest on a different side than they had prior. Try to simulate the gentle waves of a lake.

Marimo and Aquarium Safety

Many people ask us if Marimo can go into their fish tanks. We’re happy to report that Marimo are welcome additions to freshwater aquariums. In fact, they naturally absorb toxic nitrates in water and act like miniature filters, cleaning the water.

Though Marimo are safe for your fish, some fish are known to enjoy Marimo a bit too much and may peck at and eventually destroy a Marimo ball. Keep a good eye on things and see how your fish react before you decide to permanently leave Marimo in a fish tank.

Follow these Marimo moss ball care guidelines, and you should see your little guys thriving in no time! Have any questions or your own best practices for marimo moss ball care? Share with us in the comments!

A Marimo Moss Ball is often displayed in stores with aquarium plants. But a Marimo Moss Ball isn’t really a plant at all. A Marimo Moss Ball is a form of green algae that looks like a plant. A Marimo Moss Ball is soft and spongy when filled with water, and makes a great conversation piece in a tank.

How many people say they have a Moss Ball?

Other Names for A Marimo Moss Ball

In stores, a Marimo Moss Ball may sometimes be sold as: Marimo Algae Balls, Marimo Algae, Algae Balls, Japanese Moss Balls, Cladophora Balls, Seaweed Balls, Algae Balls, a Marimo Ball, Marimo Moss, and simply Moss Balls. Even though a Marimo Moss Ball is algae, its not the type of algae that will spread throughout the aquarium. The algae in a Marimo Moss Ball will not turn tank water green.

Moss Balls can often be sold on the small side, around 2 inches in diameter. Or they can be on the larger side upwards of 5 inches around. The price is usually greater the larger the Moss Ball is. And unlike most other aquarium plants, it really doesn’t shed dead plant matter into the tank.

Marimo Moss Ball Video

The Marimo Moss Ball in this video is filled with aquarium water and is resting on the bottom of the tank. These algae balls simply stay on the tank bottom as water moves around it.

Marimo Moss Ball Care Is Very Easy

The good news is that Marimo Moss Ball care is pretty straight forward. Just put Moss Balls in the aquarium and let them float around or sink to the bottom. A Marimo Moss Ball will find a spot and stay there. They can be kept alone, in small groups, or even in larger groups if space permits. They grow very slowly, and if conditions are good, they will get visibly larger over time. If the water current is strong enough it will move with the current and find a new spot to settle. If the water current is not strong enough, it may be a good idea to move it from time to time so it doesn’t flatten out on one side.

A Marimo Moss Ball can be a good fit for an established, filtered community tank. The acceptable water parameters for a Marimo Moss Ball are in the community tank range:

Water Temperature: 72 – 78 Fahrenheit
Aquarium pH: Wide range, can be slightly acidic or on the alkaline side.
Aquarium Lighting: Wide range, low to high light

Cleaning A Moss Ball

If excess debris builds up on the surface, cleaning a Marimo Moss Ball is easy. Just take it out of the tank and gently swish and squeeze it in a bucket of aquarium water. Think of it like a sponge. Squeezing it in aquarium water forces the water out and releasing it draws the water back in. If its getting a little out of round, cup it and gently roll it around. If it floats after being put back in the tank its because water is out of the middle. It will fill up and sink to the bottom again.

A Marimo Moss Ball is an interesting addition to a tank. They add green color to the setting and can draw small amounts of nutrients from the water that would otherwise feed less desirable forms of algae. Along these lines, some hobbyists suggest that they help remove small amounts of Nitrate from the water as well. They also suggest that their fibrous filaments provide small amounts of additional surface area to host beneficial bacterial. But most importantly, a Marimo Moss Ball provides tank inhabitants with something to climb on, explore, hide behind, rest under and feed from.

Some Species Like Moss Balls

Some freshwater aquarium shrimp such as Amano Shrimp and Red Cherry Shrimp are particularly fond of Marimo Moss Balls because little bits of food get trapped on the top. The shrimp pick the edible material off the surface. Most inhabitants of a community tank will not eat it per se. But its been said that sometimes Goldfish may be interesting in it as a food source, so be mindful of that.

Moss Balls are unique in that they really do not do anything, yet there is alot life-activity swirling around them. In addition to shrimp crawling all over them, its not uncommon for fish to pick little bits off food off them. And its really interesting to see snails moving across their tightly wound filaments searching for a bite to eat.

These crazy-cool little green balls of moss called Marimo Moss Balls are some of the more popular choices of live aquatic fauna you can use in designing your perfectly aquascaped betta fish aquarium. These incredibly beautiful, albeit naturally quite bizarre looking, Marimo moss balls just so happen to be incredibly easy to care for as they require practically no special attention in keeping them happy and healthy. If a moss ball can be considered happy that is… I like to think so.

First discovered way back in the 1820s, a Japanese botanist in all of his superior creative wisdom decided to name these funny looking green fur balls after a word for aquatic plant life mixed with a play on words for the word ball. Basically, Marimo means ball of seaweed or seaweed ball. Interestingly enough, Marimo moss balls are actually not moss at all. These so-called balls of moss are actually a quite rare form of spherical algae. To make things even stranger, they are relatively hollow inside. There is no hard kernel of mass inside holding all the algae in place.

Marimo moss balls take their time growing at a rate of about 5 mm per year.

Marimo moss balls take their time growing at a rate of about 5 mm per year. The freshwater lakes of Japan, Iceland, Scotland, Australia and Estonia are where these moss balls call home. In these freshwater reserves they have been documented to grow between eight and twelve inches across. That’s… actually quite impressive!

One of the almost magical qualities about the Marimo moss ball concerns the incredibly beautiful lore surrounding them. There is a legend that tells a story of two people wildly in love with each other that wanted for nothing more than to be with each other to the end of time. At one point their love was forbidden and the lovers fell into the water. As they fell into the water their hearts transformed into Marimo balls. It is said that a Marimo moss ball will bring whatever your heart desires to not only the receiver but the giver as well. This is why I buy my Marimo moss balls in bulk… 🙂

If properly taken care of, the Marimo moss ball can live to be well over 100 years old. That being said, I can imagine that I will have some very confused great great grandchildren once their inheritance reaches them. And, speaking as a fairly active betta fish enthusiast… I’m pretty sure Marimos will comprise my net worth and therefore passable inheritance. Because… my betta fish are pampered and that stuff gets expensive! But my fish are happy and that’s all that matters right?

Where Do Marimo Moss Balls Come From?
As I said before, Marimo moss balls really don’t have any special requirements when it comes to housing and maintaining them. There are couple tricks and things to consider though. Right off the bat, you really don’t want to keep your Marimo anywhere that receives direct sunlight. When you take into consideration the natural habitat of the Marimo moss ball, you start to understand that they like the really dark areas at the bottom of lakes and would really prefer not to go out suntanning is much as possible. Overexposure to direct sunlight is one of the only things you have to watch out for in maintaining a happy and healthy Marimo moss ball.

Marimo moss balls get along fine in tanks with other creatures living within. Almost all of my betta aquariums have at least one Marimo. If you have a community tank, Marimo’s are fine in that set up as well. Aquatic creatures of all types and sizes enjoy having Marimos in their tanks for several different reasons. My betta fish for example, they really like resting on top of it or hiding behind it. Sometimes I’ll find one of my fish gently rolling the Marimo across the bottom of the aquarium. It’s actually really entertaining to watch.

My betta fish for example, they really like resting on top of it or hiding behind it. Sometimes I’ll find one of my fish gently rolling the Marimo across the bottom of the aquarium.

One of the only types of aquatic creatures I’ve run into a problem with housing in the same tank as a Marimo ball is the overly curious pleco. Plecos like putting everything they can in their mouth. If you leave a pleco in an aquarium with a for Marimo long enough, it wouldn’t be unusual to find there are chunks missing from the poor little green fur ball. While not harmful to the pleco, I’m pretty sure the Marimo doesn’t enjoy it as much. There may be other fish and other creatures out there that enjoy trying out a Marimo salad for lunch, so it’s always advisable to watch the interaction of your Marimo’s tank mates closely for a while just to make sure there is no funny business going on. The worst thing that can happen in the event of Marimo ingestion is that you’ll just lose chunks of your Marimo. I do suppose if you have a very overambitious eater, constipation may be an issue… But honestly that’s overthinking it to a degree that I wouldn’t even really worry about.

Just as a side note, not relating at all to betta fish aquariums, Marimo’s can live in brackish water. There is a lake that Marimo’s are found in where the population and density of Marimos to be found actually rises within the parts of the lake with higher salinity. If you take a look on various aquatic plant websites, it’s not too hard to find posts explaining that people’s Marimos thrive in salinity up to the mid-end side of brackish conditions. All that to say, if you happen to have other fish aside from betta fish (and I’m not judging) Marimo’s are versatile and you may want to try throwing one in a brackish tank.

Learn To Love Changing Water
Regardless if you keep your Marimo moss ball in a bowl or vase all by itself (yes you can do that if you want to) or in an aquarium with a betta fish, you are most certainly going to want to perform water changes. Water changes are, in general, a pretty important thing when you’re keeping anything living inside of a body of water. Marimo’s are living organisms!

The water changes that you would normally perform in an aquarium with a betta fish in it are more than adequate for the Marimo as well. In a tank with only a Marimo in it… You might try to perform regular water changes once weekly. Especially when it’s hot outside because, you know, evaporation happens alongside rapid biological growth in warmer temperatures. You don’t want to dirty Marimo moss ball. In a jar or other container that is housing the Marimo by itself, tapwater for all intents and purposes should be fine.

Personally though, if you just so happen to have a water conditioner lying around I would go ahead and treat the water. Water conditioners are great not only for bettas but for all living organisms in an aquarium environment that are getting their water straight from the tap. Tapwater is known to have chlorine and heavy metals and other nasty stuff that living creatures don’t really like. And that is why I installed a reverse osmosis filter for my tap. Nasty stuff in the water I tell ya.

How To Clean Your Marimo Moss Ball
Marimo moss balls do get dirty from time to time. This is normal. A way to remedy a dirty Marimo situation is to clean a Marimo. Yep, you can actually clean a Marimo moss ball. Now, here’s the fun part about cleaning Marimo moss ball. What you want to do is pick up the Marimo out of the aquarium and place the Marimo in a separate clean container of water. And then the fun part. Squeeze! Gently though please. You want to squeeze the Marimo like a sponge, albeit gently because you don’t want to hurt it’s feelings, and release and squeeze and release and squeeze. You can also do this under a running stream of water. Marimo’s collect dirt, debris and algae (not just Marimo algae) not only on the outside service area but within the Marimo moss ball itself. Remember that a Marimo is mostly hollow on the inside.

If the Marimo accidentally breaks apart, it’s not the end of the world.

You can take the Marimo in between your two palms and gently roll around in your hands. While you’re doing this imagine that you are reshaping the Marimo into a perfect sphere. Marimo’s can break apart. So being gentle is pretty important. It’s kind of confusing I know. You have to both squeeze and roll and yet be gentle at the same time because they’re worried about breaking up. Yeah that’s definitely confusing. Once you have a Marimo in your hand and actually feel the resistance and the surface tension of the moss ball itself as you squeeze, you’ll have a much better idea of what you can get away with.

If the Marimo accidentally breaks apart, it’s not the end of the world. Marimo’s actually are highly resilient creatures (if you can call them creatures) and will mend themselves given enough time. While I have not done this myself, because I cannot get past the guilt associated with mutilation, I have heard of people breaking in half their Marimo’s on purpose and then reshaping them in between their palms into a ball thus creating to Marimo’s. Like I said, guilt associated, can do it. You have a Marimo moss ball living in a jar long enough, always sitting there listening to talk… you get attached.

One other thing to keep in mind is that Marimos in nature, as in in the wild, roll around on the lake floor with the current. When they’re sitting in your aquarium on your desk they don’t get a lot of that rolling around action. It’s not a bad idea to occasionally pick up your Marimo enrollment between your palms. A kind of Marimo moss ball massage I suppose. I’m sorry, my head still stuck on Marimo’s in the wild… Wild Marimo’s roaming the lake floor. I’m gonna have awesome dreams tonight!

Liking That Cool Water
if you remember the list of places I listed up above where Marimo is are found in the ”wild”, you’ll notice that those places are all cold climate habitats. The places I’m referring to in general are areas like northern Japan and Iceland. Therefore, it would stand to reason that Marimo moss balls like colder temperatures.

Now here is where you start thinking that there is a problem. Especially if you have betta fish. Because, as you know, betta fish not only enjoy warmer temperatures but actually and infactually need warmer temperatures. Between 78° and 80°F is the preferred betta fish aquarium temperature FYI. Marimo moss balls, for the most part enjoy temperatures no warmer than 75°. And even that’s a little bit on the warm and for the Marimo.

Now here’s the part that even I do not understand. All of my Marimo’s living in with their betta fish counterparts are completely fine. Natalie just fine, but thriving no less. I have had some Marimo’s for well over five years. All living in betta tanks their entire lifetime. These are warm water betta fish tanks with temperatures up to 82°. And most certainly no lower than 78°. I’m not sure if my Marimo’s are feeding off the power of love that I must be emanating towards them and that’s why they survive so well or… Maybe there’s something wrong with the information that I’ve been taught and am now passing on to you about the colder temperature thing.

What I’ve personally come to believe is that Marimo moss balls are a much more versatile aquatic plant life then many suppose that they are. While I am sure that a Marimo would rather be in colder temperature waters then the tropical waters of my betta fish tanks, it seems that my Marimo’s are still just fine. And as I said before, I’ve had some my Marimo’s for well over five years. And I haven’t been “cheating” with them and secretly replacing them in the middle of the night as they die.

One thing I do know for a fact is that my water parameters my betta tanks are kept as close to perfect as I possibly can get them 24 seven. I would therefore assume that Marimo’s can survive just fine in warmer temperature water as long as you make sure you keep up with your regular tank maintenance. Doing things like changing your water out like you should be for your betta fish.

Is My Marimo Sick?
Marimo’s can catch the flu! No, not really. But they can get sick. You can tell the Marimo moss ball is sick in the same way that you can tell that your betta fish is not feeling well. They turn a strange color. When living creatures start turning pale or gray or brown and they really shouldn’t be that color naturally, that’s a good indication that something is wrong with that living creature.

You can actually read and diagnose what is wrong with the Marimo depending on what color your Marimo moss ball is turning. The three sickly indicating colors of a Marimo are white, brown and black. If your Marimo is purple with gold speckles on it, check to see if your cat knocked over your nail polish in the aquarium. No but really, white brown and black are the colors that indicate a sick Marimo.

Why Is My Marimo Brown?
If you’re pretty green Marimo moss ball is turning an ugly brown color, you should attempt to gently clean the Marimo as outlined above in the cleaning section. One other thing that I must always do if I notice that my Marimo is turning an ugly brown color is remove him from the tank and place him (so what if I defined a gender for my Marimo moss ball!) in an entirely separate hospital tank. With nothing in it aside from the Marimo and clean water, this will surely aid in the Marimo’s recovery time and shorten the time your betta has to go without his Marimo friend

While in the hospital tank, you may notice that there are brown bits on what would be an otherwise solid green Marimo. These brown bits are often dead parts of the moss ball. If you want to try, you can attempt to carefully pick off the unsightly brown parts of the moss ball. If you do this you should add a little bit of salt to the Marimo’s hospital tank in an effort to encourage healthy growth and healing of the parts you picked out of Marimo moss ball.

One other thing to note is that if your Marimo moss ball doesn’t get moved around frequently enough, he might look fine at first glance, but if you roll him over you might notice that the bottom of the moss ball is that ugly brown color. Brown bottoms on moss balls can happen when the Marimo went for too long without receiving light on that area. While Marimo moss balls do not like direct sunlight, they are plants and they do need some light. So, just keep in mind that it’s a good idea to occasionally roll your Marimo from time to time. Also note that it does generally take a very long time of stagnation for a Marimo to develop a brown bottom. Very long time meaning periods of not moving for longer than several weeks. For the most part I’m sure this will end up being a non-issue for you.

Why Is My Marimo White?
if you look in your betta tank and find that your pretty green Marimo is now white… The Marimo is getting too much light. Oftentimes a slimy or otherwise unusual texture accompanies a white Marimo. First of all, if your Marimo is turning white make sure that you remove him from direct sunlight. If you do happen to notice that slimy textured I was talking about, generally what that means is that there is in invading species of algae that is using the Marimo surface area as a foundation to build little algae homes on top of. The invading algae is in essence choking the life out of the Marimo. It’s easy enough to deal with this algae chokehold on the Marimo by simply rinsing your Marimo often clean cold water. Sometimes you’ll notice that this foreign algae is grouped together in clumps rather than uniformly across the surface area of the moss ball. If the algae is in clumps together, you can easily remove the foreign algae with a pair of tweezers or even your fingertips.

Dealing with a white Marimo is actually not too big of an issue. As long as you make sure that the moss ball stays out of direct sunlight and is clean from any invading species of algae, your Marimo will be back to full health in no time.

Uh, My Marimo Looks Black…
the worst of the three colors that a Marimo can turn is black. If you notice that your Marimo has black spots on it, or is starting to turn black from the bottom up (or even the top down, it doesn’t matter) your Marimo is most likely decaying from the inside out. This can happen if the moss ball is been covered with an invading form of algae for too long. Just like that white algae condition I was talked about just above this. In fact, once you clean off your white Marimo, there’s a chance you might end up finding little black bits on your Marimo underneath all that white algae coloring.

If you do end up finding black spots on your Marimo, you have to literally cut them out. I generally use scissors, but you can use a knife or even try to pinch out the decaying parts with your fingers. Removing the black spots, the decaying areas, is the only course of action you have in giving your Marimo a chance to become whole and healthy once again. Once you’ve finished removing these little zombified bits of Marimo moss ball, you should take the Marimo in between your two palms and gently, very gently at this point, attempt to reroll and reshape the moss into a ball. As you can imagine, once you remove these bits and reshape the Marimo, don’t be surprised that your Marimo has shrunk.

Once you draw this nasty business of cutting apart your Marimo and reshaping him you should find that your Marimo is healthy and happy inside of about a month. Depending on how much decaying area was taken away the recovery time may be longer. If you were not able to successfully remove all the decaying bits, the decay actually can spread. So be vigilant in your quest for removing the black decaying pieces of Marimo. One last thing you might think about doing is to take the freshly operated on Marimo and place in a recovery tank until you have determined that he is all better. Placing your Marimo moss ball that is trying to recover in a community tank might not be the best way for it to recover. You would also want to place him in a tank that is colder rather than warmer during the recovery process. Try to do everything you can to match natural “in the wild” situations to encourage healing.

Gonna Buy Me A Merry Mo
~ Click Here To See Marimo Moss Balls On ~

While I hesitated even putting this part in here as it’s really not all that important in a “Marimo guide”, I did think it pertinent to at least touch on the subject. Marimo’s are not often found in all retail locations that sell aquatic pets. I know that in the area that I live in, if I don’t actually get to the store when they get the shipment of Marimo’s in, I’m out of luck for at least three weeks. Marimo moss ball availability seems to vary depending on where you’re located. But one thing I do know for certain is that they are always available online.

And that’s actually the part that I wanted to touch on. Don’t be afraid of buying aquatic plants online. I purchased plants for my betta fish aquariums on eBay and Amazon and even Craigslist a few times. 9.5 out of 10 times (probably a bit lower with Craigslist on there) the Marimo moss balls I receive from online retail outlets come in pristine health. The only reason I thought it pertinent to bring this up is that I remember the first time that I placed an order for an aquatic plant online and had major doubt the entire time I was waiting for the plant to get to my door. Then I started thinking about how these aquatic plants actually get to pet stores, like brick-and-mortar pet stores, and realized that it was no different than having it shipped straight to my door. In fact, I can’t see how it would be would be anything less than beneficial to the moss ball to cut out the middleman of the brick-and-mortar store and have the life aquatic plant delivered straight to me.

I’m not saying do not do your aquatic plant shopping at your local pet stores. I’m absolutely in love with my local mom-and-pop pet stores and have great working relationships with all of them. I highly encourage you to frequent your local mom-and-pop aqua shops if for no other reason than to build a good and long-lasting relationship with them. These people generally really know their stuff and they’re great friends to have if you have a question about something like “why is my Marimo moss ball turning purple with gold spots”. Yeah, that kind of thing.

Leave a Reply

Your email address will not be published. Required fields are marked *