I agree wig having nitrates in the 15-20ppm range for color but I'm on board with keeping the skimmer running for what's it's worth I've heard nothing but bad thing about that brand of test kits I've heard people get better results from chepo API nitrate test kits I also agree you should give AA's a try I've been dosing vod for a little now and my corals started to lighten up then I added AA's full dose for 3 days and then half dose everyother day and my color is coming back strong and my nitrate is hovering around 10ppm