There are some digital nitrate meters out there. They can get expensive though. I’ve never used it but premium aquatics makes a meter and probe combo for about 250$. You have to calibrate it for each use but needs no chemicals to test the source water. The Hanna nitrate checker is about to be released and they make hi quality stuff in the midrange price point. I think I read that it is 0-50 ppm.
A review of the strategies employed to facilitate the detection, determination and monitoring of nitrate and/or nitrite is presented. A concise survey…