Hi i have a 40 gallon reef setup i currently have 4 turbo snails and a coral banded cleaner shrimp in the tank. The rock and glass look great but ive been getting a bit of algae on the sand bed. Is there something good for cleaning this that wont eat corals, fish, snails, my shrimp? Hermits i know love snails but is there another type of crab to look for