Known Predators or potential predators:

Red Footed Snailgrazes on algae and may eat cyano bacteria.
Sacoglossa slugConsumes caulerpa sp.
Lettuce Nudibranchseeks out and consumes bryopsis.
Diadema Urchineats green hair algae and similar turf algae.
Lawnmower Blennygrazes on algae, chews on available sponge.
Regal/Hippo TangChews up zoanthids, for no good reason. May assist with algae control.
Magnificent Foxfacedevours algae: valonia & bryopsis.
Naso TangConsumes valonia.
Mexican Turbo Snailsdevours hair algae and cotton candy algae, grazes on film algae.
Gem Tanggrazes upon algae.