I'll definitely keep this in mind. My LFS tests with their kits as well and they're showing similar results as what I'm seeing, so I know I do have higher nitrates.Let me just say the API nitrate kit is junk! A while back I kept dosing and dosing nitrates because the API kit kept saying 0ppm. I couldn’t figure it out. Then I ordered a Nyos nitrate kit. Highly recommended!!! And come to find out, my nitrates were in fact much higher than 0ppm. More like 12 ppm. The Nyos kit is super easy to use and is pretty dang accurate! Especially in the lower ranges. I’d recommend this kit to anyone. And I’d definitely invest in the Hanna ULR. I personally like the H1-736 phosphorus checker. You do have to convert PPB to ppm, but that’s no biggie. I’d be curious to see what another kit says about your No3.