Oh, the clamumanity! I got the clam in February from Pacific East Aquaculture, and there is some glass-like substance covering its bysall threads. Never seen or heard of that before, but the clam is happy with it, but it can no longer attach to anything unless it bores through that piece. It was purchased in February and has been nothing but healthy since. Water params are spot-on. Tested the other day: 8-400-0. Tank has been established (but has been through upgrades) for 5 years. If the clam recovers (and I hope it does) it will be moved up higher but I'm sure it will have enough light on the sand for the time being. I am running maxspect razors at 90% over a 21" deep tank. Nothing to do but wait and observe, I guess.