I bought a small colony of about 4 green mushrooms about 4 months ago. One by one they detached from their rock and disappeared. The ones that I caught, I attempted to re-attach to a rock w/that sheer "wedding" fabric and a rubber band. They did attach and stayed there for a little while, but once again detached and were never seen again. I have one left now and am attempting to re-attach it again. I don't feel like my water flow is too much or anything. I have a 75 gal tank w/2 powerheads in either corner. I placed the shrooms on the bottom of the tank where they didn't seem to blow around. I can't understand what the problem is. My parameters are: PH 8.2, Nitrate 10ppm, Ammonia 0, Nitrite 0, spec gravity is 1.025. I have only about 90 watts of regular flourescent. Any suggestions?