"The Evil Hand" wrote in
:

But I am still unable to get a reading using my Hagen test kit, even
when I add the plant food directly into the test tube?

Does anyone know why that is?


You can read Flourish Nitrogen on a good Nitrate test kit. Chances are
your dosing is not raising the levels high enough for you to register it on
the test kit you are using. Consider using something more accurate than a
Hagen test kit to get a better reading. Seachem test kits would be a
better choice.