I'm assuming you're talking about an open brain like a Trachyphyllia. Sounds like it's... well... pooping, for lack of a better description. It's gotta get rid of the undigested stuff somehow, and it's only got one hole. So what goes in must come out. And it normally doesn't look very happy just before and after it does it.
well i still have a boring 3 gal so when they start to spread really good, ill send em over to it. what makes u think that ill have a ton?
These are my four mushrooms in my tank 10 months ago...
This is tonight...
And in reading posts here and on other boards, it's rare to find a post saying "I just can't keep mushrooms alive", but you'll often find posts saying "How do I get rid of these things once they're in my tank!!!" Don't get me wrong... I love them and would recommend them to anyone. But they do have a tendency to become somewhat weed-like.