Marimo Moss Ball for Betta Fish: The Complete Guide

If you are looking for the perfect addition to your betta fish tank, then look no further than a marimo moss ball. This plant is easy to care for and will provide hours of entertainment for both you and your fish. We have compiled an in-depth guide with everything that you need to know about these adorable plants.

A marimo moss ball is a type of algae that grows in spherical shapes. These plants are native to Japan, and they can be found in both freshwater and saltwater environments. They are typically about the size of a golf ball, but they can grow up to 12 inches in diameter.

What Are the Benefits of Marimo Balls for Bettas?

There are many benefits to keeping a marimo moss ball in your betta tank. Here are the top reasons to add one of these plants to your fish’s home:

1. They are easy to care for

Marimo moss balls are very low maintenance and can thrive in a wide variety of water conditions. In fact, they are one of the hardiest plants. They can survive in saltwater and freshwater aquariums, and they don’t need any special nutrients in order to grow.

As such, they are a great choice for beginners who have never had an aquarium before. It will be hard to go wrong with a marimo moss ball.

2. They provide a hiding place for your fish

Bettas love to have their own territory, and the marimo moss ball provides a perfect way for them to do so. This will help your fish feel safe and comfortable in their home.

I often see my male betta sitting between two moss balls in the tank. I think this is his “happy place” because he spends the majority of his time in this area. I guess it could also be because there is slightly more oxygen in this area.

3. They are cheap

Moss balls are very inexpensive, especially when compared to live plants and other aquarium decorations. This means you can decorate your tank and reap all the rewards of a marimo moss ball for under $10. I use this pack from Amazon and it has worked great for me.

So, if you are looking for a low-maintenance, affordable way to improve your betta’s tank, consider adding a marimo moss ball.

4. Removing phosphates

Bettas excrete a lot of waste into their tanks. If this is not removed, then it can lead to high levels of phosphates in the water. Fortunately, marimo moss balls are very efficient at removing these harmful chemicals. In a way, moss balls act as filters, which is why they are often recommended for tanks with bettas.

5. Reducing nitrates

Having moss balls in your tank will help reduce the nitrate levels found in water. Nitrates are toxic to fish and should be reduced as much as possible before they accumulate to dangerous levels (25ppm).

6. They help to oxygenate the water

Since the marimo moss ball is a living organism, it naturally produces oxygen for your fish tank. This will help to keep the water clean and healthy while also making sure that your betta does not suffocate from lack of oxygen. Don’t be surprised to see your betta spending the majority of its time sitting by the moss balls.

7. They look adorable

Last but certainly not least, these plants are just downright cute. They come in all sorts of shapes and sizes, so there is something for everyone. Not using moss balls can make your tank look bare, which is no fun for your betta fish.

How Do You Introduce a Moss Ball to a Betta?

You can easily introduce a moss ball to a betta by following these simple steps:

Step one: Remove the balls from the packaging and inspect them for any damage.

Step two: Wash the marimo moss balls in a separate container of tank water. This will remove any dirt that you don’t want inside your fish tank.

Step three: Soak them overnight in some tank water from your betta’s current habitat. This will allow them to acclimate to the same conditions as their new home.

Step four: Gently drop them into your tank and watch the fish have a blast playing with their new toy! Some of the marimo moss balls may float, but this isn’t an issue. You can move them into place or let them settle wherever they desire.

betta fish moss ball

Where to Buy Moss Balls for Betta Fish?

You can buy marimo moss balls at some pet stores, but they are also widely available on Amazon. These are the ones I get for my Betta fish.

It’s important that the moss balls you buy are specifically for aquariums and not for ponds. The ones marketed for ponds are usually larger and less dense, which can be harmful to your fish.

Only buy from reputable vendors that have been reviewed by other customers. If you want to ensure that your fish are safe, then it is best to stick with marimo moss balls from Amazon or another popular online retailer.

Do Bettas Fish Like Marimo Moss Balls?

Betta fish love marimo moss balls! In fact, they are often regarded as the best type of plants for bettas. The moss balls provide shelter and a place to hide, which makes the betta feel safe and secure.

As such, it’s a good idea to treat your betta to a moss ball or two. Not only will they love it, but you’ll also appreciate the low-maintenance beauty of these plants.

How Do You Take Care of Marimo Balls for Betta Fish?

Caring for marimo moss balls is fairly easy. Once you introduce the moss balls to your aquarium, it is important that they get enough light and movement in order for them to stay healthy.

The best way to keep marimo moss balls alive long-term is by ensuring that there’s a constant source of indirect sunlight in their tank. You also want to make sure that the water is moving, either through a filter or by gently stirring it with your hand.

Maintain the round shape

To maintain the round shape of the moss balls, gently roll them around in your hands. This will stop any parts from sinking down that aren’t supposed to and help you create a perfectly round ball!

Leaving a ball in the same spot may cause it to change shape over time. Hopefully, your betta fish will do you a favor by pushing your moss ball around like a soccer ball.

Give the correct amount of light

The most important consideration when caring for marimo moss balls is making sure that they get enough light. The more sunlight the ball receives, the greener it will become and the cleaner your fish tank water will be!

However, just like houseplants, moss balls shouldn’t receive direct sunlight from powerful sources. I recommend providing dappled light that comes through blinds or other objects.

How Many Moss Balls Can You Have In a Betta Tank?

I recommend having no more than three moss balls in a betta tank. Any more and they will start to compete for space and resources, which can lead to problems.

The exact amount of moss balls you put in your betta tank depends on how large your betta tank is and the number of bettas you own. I use two moss balls in my five-gallon tank and it works well. If you have a ten-gallon tank or more, then three moss balls should be fine.

Do Marimo Balls In a Better Tank Need to Be Replaced?

Marimo moss balls do not need to be replaced, but you may want to consider doing so if they get too dirty or begin to rot. If you decide to replace them, make sure you quarantine the new moss balls in a separate tank for a few days before adding them to your main aquarium.

The only time you may need to replace them is if they start to decompose or get a fungus on them. This is not common, but it can happen if the moss balls are not taken care of properly.

How Long Do Betta Moss Balls Last?

Betta moss balls last for years with proper care. As long as they have a good source of light and the water is moving, they will thrive in your aquarium. This makes them an economical and low-maintenance option for your be tank.

I’ve had the same moss balls in my betta tank for 2 years now and they’re still going strong. To be honest, I would be worried about upsetting my betta if I removed the moss balls for too long!

How Much Light Do Marimo Moss Balls Need?

Marimo moss balls need indirect sunlight to grow. If the moss ball doesn’t get enough light, it will begin to shrink and turn brown. This is why it’s important to make sure there is a good source of light in your betta tank, whether from natural sunlight or artificial light.

I make sure to leave the blinds and curtains open during the day. This allows the natural sunlight to come in and provide light for my moss balls. If you don’t have any windows in your tank, then you can use an artificial light source like a LED or fluorescent light.

What Do I Do If My Betta’s Moss Ball Turns Brown?

If your moss ball turns brown, it usually means that it isn’t getting enough light. You can try moving the ball to a different spot in the tank, or you can increase the amount of light that is shining on it. If neither of those solutions works, then you may need to replace the moss ball.

What Size of Marimo Moss Ball Should I Get for My Betta?

The size that you buy will depend on how big your tank is, but there are three different sizes available: small, medium, and large.

  • Small: This size is best for tanks up to two gallons in size
  • Medium: This size is best for tanks between two and five gallons in size
  • Large: This size is best for tanks over five gallons in size


So there you have it! The complete guide to marimo moss balls for betta fish tanks. I hope this article has helped you better understand what these unique plants can do for your fish and why you should consider adding them to your betta’s habitat.

Make sure you get moss balls specifically for aquariums and keep them in indirect sunlight with some movement in the water for best results.

You can buy marimo moss balls online or at a pet shop near you. I hope you have enjoyed reading this article and found it helpful. Feel free to reach out if you have any questions.