I had read that Marimo Balls need brackish water to thrive. I have also read the exact opposite.
So I placed two Marimo Balls in brackish water and four Marimo Balls in freshwater. Both setups had ample snails that I fed in order to provide the water with a means of fertilization. The balls in fresh water flourished and exhibited nice new growth. The balls in brackish water darkened with no new growth.
So I have placed them all in fresh water now and have abandoned the idea of Marimo Balls in my brackish shrimp tank.
Marimo Ball experiment
Moderator: Mustafa