Michael,
I do water 15% changes weekly on three tanks, siphon out the crud from the bare bottoms, tear down all the powerheads to clean them plus clean the foams in the prefilters. EVERY FREAKING WEEK
You should get very little nitrate build up in your tank with frequent (weekly) maintenance. JMHO
A couple of days ago, I checked nitrate in the tank I feed four times a day. It was only 5 ppm. Have a lot of macroalgae in that tank which probably helps keep nitrate down. No skimmer or sump, though.