Who Gives A Fish Forums

I just got my first marimo moss ball and I'm not sure how to care for it. What's the best way to keep it healthy and growing? My tank is a 10 gallon with low light and no CO2.

Marimo moss balls are pretty chill. They don't need much light, so low light is fine. Just give them a gentle squeeze every water change to keep their shape and remove debris. They're slow growers, so don't expect miracles.

Yep, what flaxton said. Also, keep an eye on your water temp. They prefer cooler water, like below 77°F. If it's too warm, they might start to brown. And yeah, they grow super slow, so don't freak out if nothing happens for months.

I've had mine for two years and they've barely grown, but they're still green and happy. Just make sure they get some water movement to prevent dead spots. Oh, and avoid direct sunlight, it can cook them.

Thanks for the tips, everyone. I'll try the gentle squeeze trick during water changes and keep the temp in check.

goldfishy wrote: ↑Wed Jun 18, 2025 1:19 pm I've had mine for two years and they've barely grown, but they're still green and happy. Just make sure they get some water movement to prevent dead spots. Oh, and avoid direct sunlight, it can cook them.

Yeah, water movement is key. I've got mine near the filter outflow and they seem to love it. Also, if you wanna speed up growth a tiny bit, try adding a little liquid fertilizer. Not too much though, they're low maintenance.

Marimo moss balls are basically indestructible as long as you don't let them sit in stagnant water or get too hot. I've even heard of people keeping them in jars with no filtration, though I wouldn't recommend it for long-term health.

Yo, marimo balls are the ultimate low-effort plant. Just toss 'em in and forget about 'em. Mine's been rolling around my tank for years with zero care. They're like the pet rock of the aquarium world, but alive.

If you wanna get fancy, you can split them into smaller pieces to propagate. Just gently tear them apart and roll the pieces into new balls. It takes forever, but it's kinda fun to watch them slowly form back into spheres.

I've read that marimo moss balls can help with water quality by absorbing nitrates. Not sure how much of an impact they actually have, but it's a nice bonus if true.