I agree with deeda, the only practical way to remove nitrate is with regular frequent water changes, not with Prime.
And filtration also has little to no effect.
I also wonder, if there was a chemical residue left in the tube between testing, I usually rinse test tubes with DI water between each test to remove residue.
Because you are dealing with parts per million, in a tiny amount of sample, all it takes is a pin head of amount of residual to skew numbers.
And filtration also has little to no effect.
I also wonder, if there was a chemical residue left in the tube between testing, I usually rinse test tubes with DI water between each test to remove residue.
Because you are dealing with parts per million, in a tiny amount of sample, all it takes is a pin head of amount of residual to skew numbers.