I'm gonna get flamed for this but oh well, lol in my tank (100 gallons ish) i have naso tangs,blue tang, yellow tang, kole tang, 2 clownfish, 8 green chromis, male& female manderin goby, 3 square anthias, diamond goby, and a handful of hermit crabs and emerald crabs, so pretty heavy bioload. I still do my checks for phosphate (which is 0.02ppm according to the hana checker) and have never really checked for nitrates. I'm using the csc 250 skimmer and it works great for my system, although i think they have discontinued that model
As for the DC pumps they are pretty good pumps, just thier controller power supplies are garbage, and to be honest when I had my dc pump i never once adjusted my pump level.