I just bought a rock with 10 mushrooms on it last week and I'm having the same problem as far as them shrinking and a couple have also detached themselves from the rock and look like they're almost melting. The 2 hairy green and pink ones are doing the best, 2 neon green ones are kind of ok but the edges are curled in and won't relax, 1 neon green has melted off the rock, 3 purple pimples shrink and then fill back up constantly and another, 1 light blue ric does this, too, and 1 other type of neon green has melted off the rock, too. The ones that have left the rock are still on the sand so I've left them to hopefully regenerate. I have this rock of them down on the sand in my 29g biocube with PC's. All other corals are doing great, these are my only mushrooms. I acclimated these for an hour by drip and for temp. I'm sure some varieties are just sensitive but what I'm wondering if there is a possibility that the 2 that detached and came apart can start up new ones? Don't mean to hijack this thread, it's just that I've been wondering this same thing. Thanks for any help.