Nitrate readings when using Kent RO right

[Keith Wolcott]

For some weeks now my nitrate readings have been zero. I don't believe that this is true. With my 10% per day water changes, I have consistently had nitrate levels of 5-8 ppm. There have been two changes since the reading went to zero. I started using Kent RO right to remineralize my RO water (before I used another brand). The second change is that my nitrate test ran out and I bought a new one. It is the same brand (Nutrafin by Hagen) with expiration date Jully 2011.

Has anyone else run into this problem? Is my test kit faulty? Does Kent RO Right interfere somehow? Is it some other problem that I am overlooking?

[chefkeith]

It wouldn't be the 1st time that a test kit's reagents were bad. In the past, I've contacted the test kit company(Sechem) and they'd send me a new reagent.

[Keith Wolcott]

Thanks chefkeith. I'll give that a try.