I have a 35 gallon reef tank with 60lbs LR, Live sand, assorted fish (2 Blue Chromis, 2 Clown, 1 Mandarin Goby and 1 Rama Grama) 2 Shrimp, enough crabs and snails and 1 sea urchin. My problem is purple velvet looking algae on my rocks. My water paramaters are perfect. Any Suggestions on how to solve the problem? Is it even a problem?