I purchased a red sea classic berlin skimmer that is rated for 200 gal tank..it is in the sump of my 65 gallon tank...initially i ran it with the suggested rios 2500 pump and yielded poor results....there for i purchased the turbo upgrade kit and after 5 weeks there is still no scum collection. i adjusted as indicated and still no result...am i wasting electricity ...or is it possible that there is limited dissolved organic carbon in the water and there for nothing to be skimmed? currently only (4) fish in tank..feed brine daily wih pellet supplemental...