most of my cichlids would eat them. But I tried one in a planted tank once and I didn't roll it around enough, so it turned brown on one side and went downhill from there.
I haven't had luck with them in any of my tanks. Something either eats them, they don't get enough light and turn brown, they get too much light and turn brown, or they aren't real marimo and they just fall apart.
You can squeeze the real ones as they are 100% algae. The fake ones are sewn together and have a hard center. It is pretty easy to tell the fakes at the store. Ordering them online is when you can get the fakes.
