<a href=showthread.php?s=&postid=9440422#post9440422 target=_blank>Originally posted</a> by EdKruzel
Being you have premium rock I will assume that it is heavily encrusted with life. Some of that life is probably algae of numerous species waiting to take off should the lighting be strong enough, plenty of nutrients and no predators. Being a nano you don't want to get too crazy with a large clean up crew, however you need enough to keep any algae in check. I'd start with 5 Nerites, 10 Ceriths and another 5 Nassarius.
Should the tank begin to overgrow or become noticeable with algae growth, first begin with more frequent water changes (life can't continue or flourish without nutrition) then add more of the Nerites and/or Ceriths. Larger snail like Astrea and Turbos are often too large for a nano and cause damage to corals as they knock them over.