I have a MR3R skimmer on my 180 gallon aggressive tank. I have never gotten the amount of skim that I thought I would be getting. Last week, I cleaned it (considerable amount of gunk build up on the tower walls), and it has not produced any skim since. It has produced foam in the column, but none of it has reached the to the collection cup at the top. Should I just give it time to recoat the walls and leave it alone? The nitrates stay about 10 ppm. I am running a DSB and algae scrubber. I have a moderate to heavy fish load and they are well fed, I would think there would have to be proteins to be skimmed