help with pyramid snails

[Ryanst]

Well I just finished reading Giant Clams in the Sea and the Aquarium by James Fatherree and in there he just says to scrub them off to get rid of them or get one of these fish. Tail spot wrasse, Green wrasse, sixline wrasse, fourline wrasse or red coris wrasse. He also said if you could get on there is a small crab that eats them Thamalita sima. How big is the clam? what kind? Do you think it might have something else too like pinched mantle?