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how many moss balls per gallon

    Live plants greatly benefit aquariums, absorbing harmful nitrates in the water and keeping your fish safe. They also offer protection for timid fish and fry and provide an attractive, lush waterscape that the viewer can take in.

    The primary drawback to living plants is that they need attention to ensure they are in good health and beautiful. The good thing is you will have living greenery inside your fish tank. This is by utilizing Marimo Moss balls instead of standard aquarium plants.

    What Are Marimo Moss Balls?

    Marimo Marimo is a Japanese word translated as “seaweed ball.”In the natural world, Marimo moss balls are located in freshwater lakes in very few areas, including Japan, Iceland, Scotland, Estonia, and, in recent times, Australia.

    The bright green spheres do not consist of moss or seaweed; they are a unique form of algae. There’s nothing solid in the ball. The entire organism is algae that slowly spreads outward at an average of 5mm per year, growing between 8 and 12 inches in diameter.

    Marimo Moss balls are challenging and virtually impossible to destroy, which makes them ideal for novices. They are also fantastic living spheres that will last for over 100 years!

    How Many Marimo Balls Are Needed Per Gallon?

    It is recommended to use up to three of them each gallon.

    Typically, 2.5-inch Marimo balls are ideal for all tanks.

    Here are some examples:

    • Four to eight are needed to fill a 5-gallon aquarium.
    • Between 8 and 13 for a tank of 10 gallons.
    • A range of 13 to 20 for the 20-gallon tank.

    Based on these figures, you’ll know that there are sufficient Marimo balls to ensure a balanced environment in your tank but not too significant that it could create problems.

    Moss balls can be up to 12 inches. However, they develop very slowly since it takes eight to 15 years to reach maturity.

    You don’t need to fret about their size anytime shortly.

    If they are too big, you could divide the ball to roll smaller portions into separate balls of moss.

    If you pile too many moss balls on one another, they’ll block each other out, and some won’t receive enough sunlight.

    In the process, they’ll fall sick and then change color.

    In addition, overstocking your tank with moss balls can not be suitable for your fish as they don’t have enough food or space to swim comfortably.

    Additionally, you cannot add additional decorations or accessories to your tank.

    Types of Moss balls

    Marimo Moss Balls – most common

    They belong to an algae family called Cladophoraceae. They develop naturally by forming algae marriages around themselves. They are straightforward to reproduce and maintain.

    Java Moss Balls

    These are made of moss balls that are secured to a core that is made of Styrofoam. Most of them have a hollow plastic core ribbed to promote rapid growth. Many hobbyists build their java-moss balls. However, keeping the desired size and shape can be a difficult task.

    Artificial Moss Balls

    As the name implies, the fakes are real! They’re simply ornaments. Why do people who are into hobbies prefer them? It could be due to their low cost and almost no maintenance work. Made entirely of plastic, they are safe hide-outs for frying.

    Benefits Of Mighty Marimo Moss Balls

    What’s the best part of saying Marimo’s Moss Balls, and why should your fish have one in their aquarium?

    Clean Tank Water

    Fish and other living creatures produce waste. Even though your aquarium’sbiological element is responsible for ammonia and nitrites, nitrates, which are the final product of this process, can be harmful to fish when levels exceed 20ppm (parts per million). Water changes that are partial help to control the number of nitrates in the water. However, living algae and plants may assist.

    Marimo Moss balls absorb nitrates out of the water for use as fertilizer. They also remove small amounts of phosphates, ammonia, and debris.

    Oxygenate The Habitat

    In photosynthesis, moss balls soak CO2 from their surroundings and expel oxygen. Therefore, if you don’t want airstones on the water’s surface the water, a few moss balls could be a suitable replacement.

    Require Super-low Maintenance

    Moss balls are virtually maintenance-free. They need only to be content with freshwater, dim or dappled light, and waste they can feed. No fertilizers are required since the moss balls take advantage of the waste your livestock and fish produce.

    Cutting the moss ball is unnecessary since they grow very slowly and uniformly, increasing in size gradually throughout the years while maintaining their soft, velvety look.

    Marimo Moss Maintains Control Over Algae Growth

    It’s a hassle when algae develop on the glass of your aquarium and grow to cover your aquarium equipment and various aquatic plant species. Marimo balls of moss consume the same nutrients that other algae do and cause them to become starving. Although adding some moss balls to your aquarium isn’t going to eliminate other algae species, it can make it harder for undesirable algae to flourish.

    Marimo Moss Encourages the Growth of Beneficial Bacteria

    The biological filter media supply a large portion of the surface area within your filtration system and the tank’s surface, both of which are crucial to the growth of beneficial bacteria colonies. These bacteria are essential in the process of removing ammonia as well as nitrites that are present in the water as well as in the maintenance of the nitrogen cycle.

    Adapts to High pH Environments

    Many aquatic plants cannot survive in waters with an elevated pH. Moss balls, on the contrary, can tolerate the acidity range of 6.0 up to 8.4 and maintain good health.

    Easy To Clean

    The regular plants may accumulate algae, which quickly gets unsightly. Cleaning the leaves of plants takes a lot of time and can destroy the plant.

    However, Marimo moss balls take in dirt and debris as sponges. This is excellent for fish tanks. But, they begin to leak out into the waters when they are filled. When doing the water change, remove the moss ball from the water tank. Then, squeeze them into a bucket or sink.

    After the ball has been cleared of gunk and water, You simply place it back into the aquarium.

    A Bettas Best Friend

    Betta fish are fascinating, intelligent creatures; however, because they are fierce, these gorgeous fish are usually kept separate. Marimo moss balls make the perfect betta fish companion!

    The fish fondly lie on their balls, using the soft, comfortable algae spheres as cushions. Bettas are also entertained by rolling their balls on the ground and removing bits of food whenever they want to take a photo after a day of play.

    Can You Have Too Many Moss Balls In An Aquarium?

    Moss balls can grow like other plants, given the proper quantity and space. You are familiar with the rules of thumb for the moss balls. You are the one who decides whether there are too many moss balls in your tank.

    You can add three times more than the rules and fill the tank with Moss balls. You will notice how the moss ball doesn’t develop as they are shaded by each other. Gradually, the color of moss balls turns brown and can be detrimental to the levels of ammonia and nitrates.

    How many moss balls are in a gallon? Do not put more than three moss balls per gallon. Then, you’ll be able to determine the right amount for your tank.

    How Many Moss Balls In A 5 Gallon Tank?

    A five-gallon tank is enormous and can house a variety of fish. If we adhere to the rule of thumb, we can put in five moss balls at a minimum and up to 15. Do not put too many while observing whether each ball is developing well.

    How many moss balls can you fit in the 5-gallon tank? It is possible to put eight moss balls into 5-gallon tanks without too excessive or too little. This amount is perfect for placing balls of moss on different edges of the tank or stacking them.

    Moss Balls In A 10 Gallon Tank

    Following the same principle, similar to the 5-gallon tank, the 10-gallon tank could accommodate between 8 and thirteen marimo balls. A 10-gallon aquarium typically includes a base of 200 sq. inches (1290 sq. cm). To cover half on the bottom, you’ll require at minimum eight balls of moss.

    Moss Balls In A 20 Gallon Tank

    A 20-gallon rectangular tank typically has about 288 sq. of (1858 sq. centimeters) for its essential in (1858 sq. cm) as its base. For total coverage of around a quarter of the surface, you’ll require a minimum of 13 moss balls; however, you can add as many as 21 marimo balls if the size is smaller than the average.

    Do Marimo Moss Balls Multiply?

    Yes, marimo balls can multiply slowly. As it grows and you’ll notice a growth on the moss balls. Don’t separate the moss balls by hand, as it could cause damage to the moss balls and cause them to die.

    Moss balls that have not been developed will have the same color as other plants. The color changes and changes as time passes. Cleaning the moss balls isn’t as tricky as other living plants. It requires very little maintenance and doesn’t require a lot of lighting…

    Caring For a Tank Full of Marimo

    Fortunately, these are extremely simple to maintain, and having a lot of them will not make a massive difference to the routine maintenance of your aquarium.

    If you have one or 100, the most regular maintenance these plants require is:

    1. You’ll first be required to perform regularly to roll them at least every week. This will ensure they remain round and won’t fall flabby on the other side.
    2. Be sure to change the water in their tanks every two days. This will ensure their water is healthy and doesn’t deplete nutrients.
    3. Also, you can take this opportunity to wash or spin them in water that has been dechlorinated to get rid of any debris that they may have accumulated.

    For a tank that is full of Marimo, it should only take a few minutes to complete. (I have a thorough list of all you need to know to take care of Marimo at my site here.)


    In the end, Mario Moss balls make a great accessory to any fish tank and will provide a lot of fun for both fish and you. They are straightforward to take care of as well. If you’re planning on adding marimo moss balls into your aquarium, keep in mind that having too many of a good thing is possible. Therefore, adhere to the general rule of thumb: Add 1-3 moss balls for every gallon. In other words, five-gallon tanks could accommodate 5-8 moss balls in a 20-gallon can take anywhere from 13-21 marimo moss balls.

    Are you adding moss balls to your tank? How many marimo moss balls for each gallon have you added to the tank? Please let us know in the comments section or contact us via email.

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