I guess it all depends. What is the size of the tank- and what is your wishlist for the tank (reef, FOWLR, peaceful or aggressive, etc) I have a plan for a peaceful reef tank. I currently have 15 banded snails and three nassarius snails. I then have an emerald crab (good for the next stage of algae- green string) a sand sifting starfish to clean up substrate, and 2 peppermint shrimp (good at cleaning up and ridding of aptasia). My cleaning crew is still small for my tank (90 gallons).