Are Moss Balls Good for Betta Fish?

Marimo moss balls can be one of the best additions to a betta’s tank. They have various benefits to betta fish, including mental stimulation and improving the aquarium environment. 

Due to their attractive looks, some enthusiasts add moss balls to empty fishbowls as a lively piece of decor. Their natural velvety greenery will enliven your space with minimal care-taking effort.

Moss balls are currently trending among betta keepers. So, in this article, we’ll explain how are moss balls good for beta fish.

Are Moss Balls Good for Betta Fish?

Aquariums with live plants are healthier for most Fish. Marimo moss balls effectively improve the water tank environment, significantly benefiting betta fish.

Lots of Moss Balls in Aquarium

Moss Balls Keep the Tank Clean

Moss balls decrease harmful nitrates by absorbing them. Nitrates are a natural outcome of breaking down the waste of your fish.

It’s difficult to control algae growth, but moss balls are one of the best control methods. They compete with unwanted algae over the same nutrients, thus reducing their growth in the aquarium.

Other algae species unsightly coat aquarium surfaces, but moss balls form clumps instead. You won’t need to clean your tank’s walls and plants from unwanted algae anymore.

Unlike most aquarium plants, cleaner snails don’t feed on moss balls. Cleaner shrimps are attracted to marimo moss balls because they feed on the nutrients and debris which collect on them.

Moss Balls Provide Oxygen to Fish

Animals in the tank inhale oxygen and exhale carbon dioxide. If a tank has no plants or algae, oxygen can only come through the water surface.

Plants and algae are essential if your tank’s filter is set at low levels. Moss balls absorb carbon dioxide and produce oxygen through photosynthesis.

Moss Balls Encourage the Growth of Beneficial Bacteria

The recesses and cavities of moss balls act as filters of nutrients in the water. They work better than ceramic discs and filter floss.

This large damp surface area hosts beneficial bacteria that break down the fish waste into nitrates (consumed by the moss balls).

If you have a new tank, you can transfer one of the old moss balls to give it a bacterial boost.

Do Betta Like Moss Balls?

Generally, betta fish are indifferent to moss balls. Still, moss balls can be the best tank toys to some bettas.

Betta fish are commonly antisocial, making it challenging to find suitable tankmates. If you put them with the wrong mates, there’s a significant risk of killing them.

At the same time, bettas are remarkably intelligent and require mental stimulation. Still, they’re unwilling to play with people or interact with R2 fish training kits.

Similar to fantails, angelfish, and cichlids, bettas will move things around in the tank to suit themselves. Some bettas view the moss balls as toys and roll them around the tank for amusement.

If we have enough moss balls to form a wall in the tank, some bettas prefer to use it as a hiding place (even if you provide other hiding places).

Thus, we can assume that some bettas are happier with moss balls, but not all.

Moss Ball on White Background

Are Moss Balls Harmful to Betta Fish?

Moss balls are soft, so there’s no risk to the delicate fins of the bettas. Their pace of growth stays within control, so they’ll never obstruct swimming areas for fish.

Care-Taking of Moss Balls

Mosses are flowerless plants, but marimo moss balls aren’t actually plants. They’re a colony of freshwater algae.

We prefer them over other aquarium plants because they don’t have to be pruned of dead leaves or anchored to the ground.

Do Moss Balls Need Food?

Moss balls don’t need food or fertilizers. Instead, they need some minimal conditions to make their own food.


Similar to plants, algae require sunlight and carbon dioxide to photosynthesize. The tank has to receive good indirect sunlight throughout the day.

Be cautious of direct sunlight because it can turn your moss balls brown. If you notice the browning of one side, scrape off the brown layer, then roll the moss ball to the other side.

If the moss balls are fading in color or turning yellow, this means that they need more light. Move them to a brighter spot.

Carbon Dioxide and Nitrates

Similar to plants, moss balls need carbon dioxide and nitrates. If the moss balls aren’t growing, this can indicate that they’re not absorbing enough of those required elements.

First, divide the moss balls into smaller clumps to make sure carbon dioxide and nitrates are flowing through the dense center of the ball. If they still don’t grow, you’ll need to move some of the moss balls to another tank.

Suitable Temperature

Although moss balls are difficult to kill, they don’t do well in all temperatures. Their optimum temperature ranges from 72°F-78°F.

If you want to stay on the safe side, stick to the colder temperatures of the range. Marimo moss balls are indigenous to the cold waters of Asia and Europe.

Can You Cut a Moss Ball in Half?

You couldn’t have thought that this benefits moss balls, but cutting them in half is the way to propagate them like other algae.

Squeeze the moss balls, give them a rinse, then cut them in half. They need to be periodically rolled over to maintain their ball shapes.

Marimo moss balls can reproduce naturally, but they take time to reach the required size. When they do, you’ll notice a small lump growing the existing ball, later falling off.

Wrap Up

Moss balls are harmless algae, and they pose no danger to your bettas. They’ll improve their water environment and give them some quality playtime.

Now that we’ve explained how are moss balls good for betta fish, you might be compelled to buy some for your bettas.

They’re low-maintenance, but make sure to provide them with their required conditions to thrive.