I've begun to question the validity of my Nitrate test bottles. No matter how long I shake the bottles, I continously get high Nitrate readings in my tanks. I've done tests on my tap water and those also get high nitrate readings. That might suggest that my tap water has high nitrates, BUT my 37 gal
is a highly planted tank. It would be reasonable to expect that tank to have lower nitrates but according to the API test bottles, it does indeed have high nitrates. Now, I know the Nitrate test is notorious for having issues do to user failure, but I'm just not convinced that is what is happening because when I take a water sample to my LFS
or use test strips, my nitrates in that tank are always <10ppm. Thoughts? Do they even sell a Nitrate test that I could buy and test against mine? I've seen the ammonia test bottles but not any of the other tests packaged singly.