There is a very easy solution to controlling pyramid snails as there are with most nuisance predators. For every nuisance critter there is a predator. Remember that our tanks are by definition "unnatural." We do not have the biodiversity in them that a reef does. In other words, there are no checks and balances, and we often are lacking the necessary predators to prevent issues like these. In the case of pyramid snails, there are several wrasse species that will make a good meal of them. My preference is a tail spot wrasse that also just happens to be my flatworm "hit squad."