What jraker said. The key is to get a lot of reproducing snails, so you have multiple sizes. The strombus are great, but you may not like the plague of snails look. Ceriths are awesome. You'll probably need to manually remove the gha for a while, until the snails catch up. Also, I wouldn't add hermits if you add snails. They kill the snails, and aren't as good at algae removal, in my experience. Hermits can work, as long as there is no other food. If food is added, they'll eat that, rather than algae.