Marimo Moss Ball Aquarium Care Guide

Marimo Moss Ball Aquarium Care Guide

Marimo moss balls are said to bring perfect heart’s desire to both giver and receiver. These beautiful royal plants can easily live 100+ years. For this reason, Marimo make wonderful family heirlooms.


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Sacred Plant Co Marimo Moss Ball Care Guide


3 Simple Steps To Keep Your Marimo Moss Ball Happy



Keep your Marimo where they will receive low to medium indirect light. You must protect marimo from the direct rays of the sun, as Marimo can easily turn brown if they are getting direct light! Also keep in mind that direct sun will be intensified by glass marimo enclosures which can heat water quite quickly. Remember - these guys are native to cool lakes, and should be kept cool.



Changing the Water Change your aquarium water once every two weeks

using regular tap water (for best results, allow water to sit out for 24 hours prior to changing the water). You’ll need to change the water more often in summer, as it will heat and evaporate more quickly. Clean your marimo enclosure with a brush if algae begins to grow on tank surface.



If your marimo moss ball begins to turn brown, make sure they’re moved to a cooler location with less direct light. They will recover and turn green again on their own. If not, you may add a tiny amount of aquarium ocean salt.

Top view of marimo moss ball


Marimo Moss Ball FAQ

Why is my Marimo Ball Floating? More than likely, your Marimo ball has an air bubble trapped inside of it. That air bubble is likely causing your marimo moss ball to float! Gently squeeze your marimo ball to pop the air bubble. Generally, Marimo will sink to the bottom of their tank within 1-2 days of being added to an enclosure.


Can Marimo Moss Balls Survive Outside of Water?

Yes! Marimo moss balls can survive without water if kept in plastic or a closed jar for several days, as long as they aren’t allowed to fully dry out. Plastic bags are the easiest way to travel with Marimo moss.


How Do I Keep My Marimo's Round Shape? In their natural habitats, the waves and currents of the lakes gently rotate and roll the Marimo balls along the floor of the lake. To ensure that your Marimo keeps its round form you’ll want to gently agitate the water in your Marimo enclosure, with the goal that when your Marimo balls settle back to the bottom, they rest on a different side than they had prior. Try to simulate the gentle waves of a lake.


Are Marimo Moss Balls Safe In A Fish Aquarium? Many people ask us if Marimo can go into their fish tanks. We’re happy to report that Marimo are welcome additions to freshwater aquariums. In fact, they naturally absorb toxic nitrates in water and act like miniature filters, cleaning the water. Though Marimo are safe for your fish, some fish are known to enjoy Marimo a bit too much and may peck at and eventually destroy a Marimo ball. Keep a good eye on things and see how your fish react before you decide to permanently leave Marimo in a fish tank.


Follow these Marimo moss ball care guidelines, and you should see your little marimo moss ball thriving in no time! Have any questions or your own best practices for marimo moss ball care? Share with us in the comments!