Cannot get Nitrates down-advice please, so frustrated

[Rybren]

Oh, I will buy another NO3 test to see if there is any difference. Thanks for your sharing

If you get another Salifert test, you may end up with the same problem. I don't know whether all cards are bad, or just certain ones. My kit has an expiry date of 04-2018

 

[Tanthaitrung]

If you get another Salifert test, you may end up with the same problem. I don't know whether all cards are bad, or just certain ones. My kit has an expiry date of 04-2018

No, I mean buying another brand and try comparing