11 Benefits of Marimo Moss Balls in Aquariums You Mustn't Miss

Marimo moss balls are small balls of green algae that have the velvety texture of moss. They are a very popular choice as aquarium plants due to the numerous benefits that they provide to their aquatic environment. So, what exactly does a marimo moss ball plant do? Let’s find out…

Golden fish (Carassius Auratus) in a bowl

Quick Fact
Lake Akan in Japan and Lake Mývatn in Iceland have been declared as a national park and nature reserve respectively, to conserve marimo moss, which is a protected species in both countries.

Marimo moss is a filamentous species of wild algae which is native to Japan and some parts of northern Europe. Its name comes from the Japanese terms ‘mari’ which means bouncy ball, and ‘mo’ which means aquatic plant. Strands of this algae are known to float around in freshwater bodies where there is enough nutrition for them to propagate. Marimo moss can be found growing on rocks, and floating on water as strands or spongy, velvety balls that are found on the beds of lakes and rivers. The moss propagates by division, where each individual strand is capable of gradually creating a new ball all by itself.

Live plants are an important part of an aquarium, as they create a conducive environment for aquatic animals to grow in. However, most of these plants are hard to maintain, and they have short lifespans, making it quite a bother. Still, none of these issues will trouble you if you choose to go in for marimo moss balls. Besides being easy to care for, this moss has many other benefits and uses in a fish tank.

Marimo Moss Ball Benefits in Aquariums

1. Absorbing Pollutants

Marimo moss balls absorb pollutants such as phosphates, nitrates, ammonia, and other waste solid debris in the surrounding water. Although they cannot completely replace a water change and filtration system, a large ball can help significantly in smaller aquariums.

2. Creates Oxygen

Like any other plant, marimo moss absorbs carbon dioxide and releases oxygen through the process of photosynthesis. Although the amount of oxygen produced is less, it is still helpful in maintaining a healthy environment in the aquarium.

3. Adds Helpful Bacteria

Like sand and plants in an aquarium, this is a great source of helpful bacteria, which contributes in maintaining good nitrogen and phosphate levels in the water.

4. Carries No Parasites

Unlike other items and aquatic animals that have to be added to a fish tank, marimo moss is usually parasite-free, and can shelter your fish from harm.

5. Resilience

These balls are very hardy and do not require any care, and can thrive in varied surroundings as long as you regularly perform minimal maintenance in the tank.

6. Prevents Growth of Other Algae

One of the regular problems faced by aquarium owners is the film of green/brown algae that spreads all over the glass, sand, and other fixtures in the tank. This problem can be completely solved by wiping out the algae and adding balls of marimo moss to the tank. Marimo moss is an algae too, and hence, it absorbs all the nutrition required by other algae, thus stopping the progress of these intruders in their tracks.

7. Free Floating

Most items in an aquarium need to be fixed or anchored, and this makes them a hindrance while cleaning the tank. However, marimo moss floats freely, making it easy to clean around, thus reducing the time you spend on cleaning the tank.

8. No Dead Plant Parts

Most aquatic plants need to have their dead or dying parts removed regularly to stay healthy. However, there is no need to do this for marimo moss balls, as they almost always stay rich green.

9. Salt Tolerance

Majority of the freshwater aquatic plants cannot thrive when the salt level in the water is relatively high. However, wild marimo moss is found largely in brackish water, giving it an advantage of high-salt tolerance.

10. Great for Aquarium Creatures

Since these balls collect a lot of debris, they turn into a favored place by pet shrimp and snails, which feed on the debris. Due to their free-floating nature, active fish such as gouramis love to push them around and use them as toys. This way, these plants benefit the animals as well as themselves, making them a wonderful addition in an aquarium.

11. Resistant to pH Changes

Unlike other plants, they can thrive in high or low pH water, without the need for any special adjustments.

Marimo Moss Ball Plant Care Tips

For marimo moss to thrive, the tank should be kept in a cool place, out of the reach of direct sunlight, and the temperature of the water should not be too warm.
A singular ball is nowhere enough to make a considerable difference in the conditions of a tank. Make sure you have enough or a mix of other plants to support the functions of the moss effectively.
Marimo moss grows very slowly, and takes a few years to grow to a large-sized ball. However, if you find that the size of the ball has become too big, cut it into smaller pieces and roll them into small balls.
Be vary of cheaper substitutes, such as java moss rolled over a ball of foam. They are not as resilient or effective.
There is no need to put any specific food or fertilizers for the moss, as it absorbs all the nutrition it needs from the waste of the fish and fish food.
They tend to absorb a lot more waste and debris than they can consume, the remainder of which is stored inside them. So, when you clean the tank or change the water, take out the balls and squeeze out the waste from them in a sink or bucket. You can then put them back in the tank. Performing this process regularly will keep the algae healthy.
The lower side of a marimo moss ball may turn yellow or brown over time. To avoid this, move the ball and turn its position once in a while.
Goldfish are chronic destroyers of plants placed in fish tanks. So, keeping a marimo ball in a goldfish tank is a waste of time and money.

Marimo moss balls are a great overall option for those aquarium enthusiasts who find it difficult to maintain aquatic plants. These plants can be used for decorative purposes or to add plant life into your tank. In short, getting this plant has no negatives, and will only be beneficial for your aquarium.