For 3 days it's looking unhealthy. Is this normal? Nothing added in the tank. do 10 weekly water changes. water par:
Ca 410
alk 3.89
KH 10.9
PH 8.05
Nitrire 0
Nitrate 0
Ammonia 0
That doesn't look good. Is it still solid? See if alot of dead tissue falls off when you move water by it with a turkey baster or your hand or some thing. If this is the case, I've had luck putting some water from the tank in a bucket and washing the dead tissue off. You don't want all that dead stuff in your tank if it is in fact dying........
Is it possible it didn't like being a host for your clown? Some corals can't deal with the stress of being rubbed and rolled on like clowns like to do. Just an idea.
IME, i've never had a toad stool that would put up with a clown fish nipping at it and swimming in and out of constantly. I know some people have had success with this, but I never have. You are much better off using a BTA for your clown host, depending on your lighting and water quality of course......