i have a 4 some of triggerfish along with a mix of other fish in my tank. they are a niger, piccasso, blue jaw and a pinktail. i have had bad experience with the triggers and inverts, crabs and shrimp didn't make it. i have seen them pick off some small snails that have come with my LR, but i have not added any larger snails with any success. then just cause i got a turbo snail the other day and they didn't give it more then a close inspection. the snail is still alive and it has done some "cleanning". i want to try some more inverts for this tank. how many snails should i get? i will try hermit crabs again, but i will see how the addition of more snails go first. the next tank they will be in is a 120gal or a 125gal.