Currently I have 3 large turbo snails and a conch in my tank. I've seen recommendations of up to 10 turbo snails for a 30 gallon tank. Would you agree? What would be a good limit for my tank? I have a lot of rock surface, so I'd imagine at least 5 would be a good start, but I don't want to over populate and possible starve them! What are some of you using in your tank for algea/detritus control?