What's eating my corals?!!!

[franknfeather]

Something is eating my zoos and mushroom polyps I had bought some huge turbo snails and thought it may be them. I got rid of them weeks ago but the coral is still disappearing. Lost some awesome smaller zoos and blue spotted + red mushrooms.

Here is what I have.
Maroon Clown
Hippo Tang
Carpenters Wrasse
Firefish
Mandarin Dragonet
Citron Goby
Cleaner Shrimp
Peppermint Shrimp
Small Turbo Snails
Nassarius Snails
Emerald Crab
Blue, Red and Yellow tip Dwarf Hermit Carbs
Long Spine Urchin
Any ideas are welcome.
Thanks Everyone.

 

[coraljunky]

Possibly the water quality. Parameters? Or predators that are not easily spotted.

 

[franknfeather]

Water parameters are fine. As they are not dying or dropping off the rocks. Thursday morning I had a nice big red mushroom the size of a nickel and when I got home about 8 hours later he was completely gone. Same thing today. I had about 6 eagle eye zoos this morning and they were all gone this evening.

 

[nycbob]

the surest way to find out is check on ur tank often. it could be the peppermint shrimp or urchin.