What are the Key Differences?

Java Moss Ball vs Marimo – What are the Key Differences? 

Java moss balls and marimos are the first things that come to mind for adding decors to aquariums. But many people confuse java moss balls as marimos. They are, in fact, very much different from each other.

So, what are the key differences between Java Moss Ball vs Marimo?

Java moss balls are artificially made whereas Marimo is found naturally. Marimo has more special effects like they are seen to float and dance which is aesthetically pleasing. They are also higher pH and disease tolerant compared to Java moss ball.

Well, these were just a couple of differences between them. There are a large number of other differences which we’ll talk about in detail.

So what are you waiting for? Let’s see what we are offering ahead!

Mythbusting 1: Marimo is Actually a Moss!

No. Marimo is not a moss. In fact, marimo is one kind of algae named Aegagropila linnaei which is green and velvet-like. Marimos’ unique round shape can confuse people to think it’s java moss balls. But in reality, it gets this round shape naturally. And it’s not moss, but green algae.

Mythbusting 2: Java Moss Ball and Java Moss are Different

Java moss ball is actually java moss tied to a styrofoam ball. It’s artificially made in order to have floating java moss in the aquarium. It’s suspended in the aquarium with a weight attached to the fish lining like clear fishing wire. It can be placed at any height there.

These java moss balls are a great piece of decoration for aquariums. They also act as refuges for small fish and fries. 

Quick Difference

well, I actually love to make instant decisions without wasting any time. But as we’ve already seen it’s not always that easy. However, at least here I can help you with that part. How?

Here I’ve come up with a quick comparison table. Take a look make your decision within a minute!

Wait I’ve something more for you! A bonus chart to make things more clear. Take a look!

Got enough ideas already? Well, ideas are never enough. They just keep coming. That’s why we’re not stopping here either.

So let’s get to the business-

What is the Difference Between Java Moss Ball and Marimo? Let’s Dive Deep

What is the Green Marimo Moss Balls and How to Keep It?

Source: https://www.senzeal.com/

Now that you’ve seen the quick difference between java moss ball and marimo, it’s time to dive a little deeper. We’ll now discuss their various features in detail. Let’s see.

Appearance, Texture, and Size

They are both similar in appearance. However, they are not in the same family, unlike when we compared two anubias plants. They have slight differences in their size and texture. Let’s take a look at them in detail.

Java Moss Ball

Java moss balls have a round shape appearance just like natural balls do! The ball attached to the moss actually decides its shape. But it’s most commonly seen as round rather than oval or any other shape. And Java Moss and Marimo, both of them match each other at this point. Java moss ball texture is squishy if held. That’s because the ball is empty in the center.

If you press them, they will feel squishy and water will come out of them. Java moss balls are artificially made. So its size varies accordingly. However, it’s most common to see their size ranging from 2-3.5 inches.


Marimo too has a round shape like java moss balls. But its round shape is perfectly natural. It has no human interference like a java moss ball. It’s also a bit squishy. But, it has a firmer grip than the java moss balls. That’s because its center is not hollow like moss balls.

They come in a variety of sizes. Since these are natural algae, they grow on their own. The most common sizes found are between 1.80- 2.30 inches. These balls are 8-14 years old. They are usually sold at this size.

However, they can grow up to 4 inches too. Those are older in age(almost 20 years). The largest marimo ball size is 37 inches or 95 centimeters. 

Marimos are more appealing to see than java moss balls. They are softer too. And you cannot get the perfect natural round shape out of java moss-like marimo.

Winner: Marimo

Suitable Tank Size

When it comes to tank size, both java moss balls and marimo balls can be stored in up to 20 gallons tank. You can also increase it further, maintaining a minimum of 1 ball for a 1-gallon ratio. Let’s see-

There need to be 1-3 marimo or java moss balls in 1 gallon of water. In this way, you can calculate the required number for yourself. However, we’ve listed that for you-

In this way, you can place your number of java moss balls or marimo. The main concern here is not to make your tank crowded. If you have fish in your tank already, they will need their free space for a healthy life. So don’t put an excessive number of balls in the tank. 

Long story short, since both java moss balls and marimo are similar in size, their amount placing is quite similar.

Winner: Tie

Lighting and Temperature

High temperature is not suitable for both java moss balls and marimo. They can’t handle a temperature higher than their threshold. If we talk about lighting, none of them require high-intensity lighting either. Let’s see-

Java Moss Ball

Java moss is suitable in a tank that is 158-170 F. If the temperature goes beyond that, their growth will be slowed down. You might be wondering that java moss balls are artificially made. So how will they grow?

Well, the alive moss part is still attached to the ball. But they will still have growth on the surface at a higher temperature.

Don’t go beyond 187 F if you want them fluffy on the surface. That’s cause it’ll slow down their growth. For lighting, they don’t need much lightning to grow. 3-4 hours of normal household light or aquarium light is fine for them.

Truth be told, we haven’t used household lights for moss balls actually. However, we’ve tried out different aquarium lights in different tanks. And we’ve got a few preferences-

  • We like this aquarium light because it gives the best bang for the budget.
  • This aquarium light is really premium and 
  • This light will just do the work if you’re on a tight budget. 

Aquarium lights are better because you can use them for different plants. More importantly, these are better for aquascaping. 


Java Moss Floating Balls DIY Kit

Source: https://www.tropicalworldusa.com/

In the case of Marimo, they are more vulnerable to a higher temperature than java moss balls. They should be kept at temperatures between 161 F and 170 F.

When the temperature gets a bit higher, marimos can burn themselves. They tend to burn themselves under direct sunlight. So it’s recommended to maintain temperature for marimos.

If we come to the lighting part, it’s the same as java moss balls. You can keep them under normal MingDak LED like or bright fluorescent bulbs for 3-4 hours. There’s no harm found if the lighting is done for 12 hours either

But make sure it doesn’t go under direct sunlight. Otherwise, it’s most likely to burn itself. Indirect sunlight is fine for them.

However, as java moss handles temperature better than Marimo, java gets the upper hand here.

Winner: Java Moss Ball


pH is an important factor when it comes to aquatic life. It helps to maintain their growth and appearance. In this case, pH also helps in disease tolerance. There’re optimal pH requirements for both java moss and marimo balls. This will ensure their well-being. Let’s see more-

Java Moss Ball

In the case of java moss balls, their Ph level is the same as for java moss since they are made of it. It’s necessary to measure the PH to know if it needs to be changed or not. That’s why as an aquarist I always keep a pH thermometer in my house. Let’s introduce you to some of the best thermometer I had good experience with-

Their ideal pH measurement is 5-8. It’ll be problematic if the PH range is not maintained in this case. So, Try to maintain this range. Otherwise, it can hamper their nutrient intake capability.


In the case of marimo, the optimal PH level is 6.5-9.0. Any PH between this range is preferable for them. But if you want to be more constant, you can keep your pH at 7.5 for best results.

How to maintain PH

In order to maintain pH in your aquarium, you can do a couple of things. But before setting up the right pH it’s necessary to check the pH level first.

Here’s our recommendation to safely measure the pH of your tank-

  • Now that you know the pH level, you need to either lower it or higher it. In increase pH, you can follow these below-
  • Add 1 teaspoon of baking soda per 5 gallons of water. It’s the most common way of increasing pH. When adding it, make sure to remove the fish from your tank.

If you want to decrease pH level, follow these-

  • Decrease co2 levels and aeration.
  • Add driftwood

By following these, you can maintain a suitable pH for your java moss or marimo balls.

Winner: Tie

Setup Method

Neither of these two aquatic balls requires a high-end or expensive setup. In fact, they are extremely cheap to set up. There are small differences in their setup method. Let’s see them in detail-

Java Moss Ball

In the case of java moss balls, you can choose any tank as per your need. If you have a large tank, place java moss balls according to gallons as we showed. You may or may not put fish along with it. Make sure to give your fishes enough space in presence of java moss balls. They should not feel crowded.

You can put them at any height of the tank. But for this, you need a couple of things. We’ve listed a complete setup for you. This is the most minimal setup for java moss balls. Here it goes- 

Now what you need to do is attach the fish lining to the driftwood in the bowl. This is so that it can hold the java balls at a certain height. Now tie the balls with this fish lining at the height you wanna keep them. And you are all done. We’ve already talked about the lighting and temperature parameters.

If you have a large aquarium of 15-20 gallons, it’s okay too. You just add a few more java moss balls in there. And attach them to the fish lining as we mentioned before.


Marimo has a similar setup requirement like java moss ball. You can easily grow them in your aquarium.  But there are some small differences between these two.

You can use any sized tank for marimo. Follow our marimo per gallon instruction as we mentioned before. You can even keep them alone or in groups in the tank. It’s according to your wish. 

Marimo is a bit more sensitive to light than java moss balls. If there’s too much lighting they can burn. To have any LED or fluorescent bulbs is enough for them. You can keep them on for 3-4 hours. If you are not getting enough growth, try 8 hours of lighting instead.

They don’t need to be suspended via fishing lines like java moss. Put them in the water and they will find a suitable spot for them and remain there. You can use a small 3-gallon bowl if you want to keep only marimo there. Or you can have a 20-gallon aquarium too with fish.

If you want, you can keep marimo in a terrarium too by making a pond. It’s very easy to make. And it would look aesthetically pleasing too.

Winner: Tie

Growth Rate & Propagation

The legend of your Moss Ball Pet – Moss Ball Pets™

Source: https://mossballpets.com/

Both java moss and marimo are slow growers in general. But they have their differences. Let’s see-

Java Moss Ball

Java moss ball is basically some java moss attached to a ball. So the growth of this is just like java moss. But keep in mind that the moss ball size is not getting any bigger. It’s just the leaves will spread and grow. It will look like a green hairy ball once it grows.

They are seen to grow much faster than the marimo balls. Within 2 months, the java moss balls will grow by 1 or 2.5 inches. If you don’t want them to grow, you can always give them a little trim.


On the other hand, marimo are comparatively slow growers than java moss. They grow at 1mm per year. As you can see, this is a very slow growth rate. But do keep in mind that the growth of marimo moss balls is different. Marimo grows in its diameter as a whole. Whereas in the case of java moss, the leaves just grow, not the ball.

Many people ask the question “Can I cut my marimo ball in half?”

Yes. You can split or cut your marimo ball in half. This will give rise to 2 new marimo balls which will now enlarge with due course of time. You can simply split them apart with your hand rather than with a knife. 

Nonetheless, you can use some healthy fertilizer for your marimo growth. Let’s take a look at those-

Winner: Java Moss Ball

Care & Maintenance 

When it comes to car and maintenance, it acts as a decision-making factor for many. To make it even easier for you, we’ve listed them differently. Let’s have a look-

Java Moss Ball

Maintenance and care for Java Moss ball-

  • Make sure to change the water every 5 or 6 days.
  • Trim down leaf growth on the balls every 2 or 3 months or they will look messy and tangle themselves.
  • Try to keep the water at a low temperature like 21 C. At higher temperatures, it will grow slowly 
  • Java moss balls are likely to grow algae on them. For that, use a toothbrush to gently clean their surface if alga forms upon them.

These maintenance tips are very easy to do. So make sure to follow them.


Maintenance and care for Marimo-

  • Roll your marimo balls in your hand every time you change the water. This will ensure that they don’t go out of their round shape.
  • Make sure to change water every 2 weeks 
  • Don’t put them under direct sunlight or they will burn themselves. Keep them under indirect sunlight or low to medium lights.
  • If it comes up to the surface give it a squeeze. That’ll clear the bubbles that are trapped inside it.
  • Another thing to keep in mind is that the bubbler of your aquarium doesn’t come in the way of marimos. You can keep the bubbler in one place rather than roaming around near the marimos.

These are the maintenance tips for marimo. These will increase their longevity.


Marimo Moss Ball (Aegagropila linnaei) – AquaSnails

Source: https://www.aquasnails.com/

Both marimo and java moss balls add a lot of benefits to your aquarium. You will be surprised by the number of benefits these small things can add. Let’s see-


Marimo provides a number of benefits to your aqua space. Let’s take a look.

  • Prevents further algae growth by taking up the nutrients for algae itself.
  • Provides aeration in the tank
  • Can float on its own
  • Is highly compatible with shrimp and other tank mates
  • Contains beneficial bacteria
  • Reduces nitrates in the water
  • It doesn’t carry any parasite with itself
  • Is salt tolerant
  • They become a feeder for small fish by taking in the debris of food and nutrients from the water.
  • Is pH resistant

These benefits are usually unexpected from small algae-like marimo.

Java Moss Ball

Now, let’s see what benefits Java Moss Ball brings in-

  • Sucks up pollutants and debris as its food.
  • Reduces the growth of algae by many folds
  • It can block light for the blackwater fishes
  • Reduces Ammonia in the tank
  • Reduces the number of toxins present in the water
  • Small fishes can use it as toys

Java moss balls act as good filtration media for your aquarium.


Here I’ve summarized the end result in the following table. Let’s go through everything one more time.

Is it a Concern if Java Moss Ball or Marimo Float?

It’s not a concern if Java moss balls float. In fact, they are supposed to float due to their hollow space inside. However, if marimo balls keep floating or coming to the surface, there are air bubbles trapped inside them. If it happens, you need to take it out and squeeze it. This will get rid of the air bubbles trapped inside.

Can You Make Java Moss Balls at Home?

Yes. You can make them at home very easily. Let’s see how you can do so-

In order to make a java moss ball, you are gonna need a ping pong ball and some threads. Simply put some java moss on top of the ping pong ball and tie it off with threads gently. You can either tie them or add them with glue. And you are done! 

Put the balls in the water and tie them down with the fishing line as we mentioned earlier. 


Now we’ll be answering some of the most frequently asked questions about these 2 balls.

How can you tell if a Marimo Moss Ball is real?

You can tell if a Marimo Moss Ball is real by looking at its shape. If it’s perfectly round, then it’s probably a fake. There’s just moss covered in a ball. They should be lumpy and out of shape in a few places.

How do you clean moss balls?

Put them under slightly warm water and give them a squeeze. It will remove the dirt and other pollutants if stuck any inside them. After that, it will take in clean water again inside it.


We hope we’ve been able to help you with java moss ball vs marimo. Now you know their differences. You should also be able to choose the right one between them now.

Thank you for staying with us till the end. Do let us know if you have any queries!

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