Does anyone else have experience with HR Nitrate tester not working

[BudgetR33f]

I tried two boxes of reagents and both of them always read differently and too low. I followed the instructions carefully and they don‘t expire for a couple years. Is there a way to fix this?

 

[Dan_P]

I tried two boxes of reagents and both of them always read differently and too low. I followed the instructions carefully and they don‘t expire for a couple years. Is there a way to fix this?

I presume both boxes were from the same lot and that you are 100% sure the sample had at least 1-2 ppm NO3.

If the chemical in the pouch is not an almost white and free flowing powder, I think there is a quality problem. Contact Hanna.