[butchblack]

Does the nitrogen in liquid fertilizers affect a nitrate test? I checked mine shortly after doing a water change and dosing liguid ferts and it was up a bit, between 40-80 ppm. I ran out of nitrate test solution, so I can't see if it went down significantly. The next time I add liquid ferts I will test before and after to see what the difference is, but until then I'm wondering if anyone has any experience with it? It's my heavily planted 75g tank.

 

[Greggz]

Does the nitrogen in liquid fertilizers affect a nitrate test? I checked mine shortly after doing a water change and dosing liguid ferts and it was up a bit, between 40-80 ppm. I ran out of nitrate test solution, so I can't see if it went down significantly. The next time I add liquid ferts I will test before and after to see what the difference is, but until then I'm wondering if anyone has any experience with it? It's my heavily planted 75g tank.

Short answer is yes. Test will read NO3 from fertilizer.

In fact, you can even make a calibration solution to see if your test kit is accurate. API can be wildly off.

Salifert gives consistent readings and always calibrates correctly.