Was on the other day and asked some advice on our sudden death of sea urchin, crab, banagaii cardinals, foxface etc. Now we've noticed that our big tridacna clam is unhealthy and appears to be infested with pyran snails. He is attached to a rock so can't get him off for a scrub or fresh water wash. Anyone have any ideas? Do yellow wrasse work for cleaning? Is our whole tank invested now or will these snails leave the rest of the tank alone?