Ok, so here's the official update and resolution to my dilemma. The culprit? My beautiful orange spotted rabbitfish. After going a couple months with no zoas in the tank, I ran across some hornets just I couldn't pass up. So I made a little shark cage for them, covered them and waited. I first noticed my yellow cuke hanging around the cage, so I put him in the sump - I didn't really think it could be him but wanted to remove the variable... I waited some more, because if it was snails or parasites, they had full access to the zoas and I'd start to see an impact.. Nothing.. I waited some more, and when I was sure they were okay, I pulled the cage off and watched. Not a few minutes later, the rabbit came over and ripped a piece off of one of the outermost heads!

That rabbit is now back at the LFS. Sucks too, cause I loved that fish! Oh well, this hobby is full of trade-offs!

Anyone got any blue-tubbs for sale?? lol