I have some sort of thing in my tank. So far it has killed one turbo snail, and one clownfish. I have not seen the thing, but i know my water is fine (everything where it needs to be, water parims are fine). The total stocking (that i know of) is 1 clownfish, 3 green chromis, 1 firefish, 1 cardinal fish, 4 hermit crabs (the really small ones), 1 turbo snail, 4 small snails, 1 small anenamy, 1 small feather duster (i think). PLZ HELP ME! Thanks in advance.