Hanna Marine nitrate test

[ptrusk]

Are these tests really accurate?

Background. Some months ago, I bought the egg because I got tired of guessing on red sea/salifert tests. Results on the hanna were 30-40. That is about normal for this tank. After the initial reagents ran out, i replenished and the next batch of reagents were noticeably higher. I am guessing like 15%.

I purchased a new batch of reagents and just tested both. New reagent was 47.7, the last suspect lot was 56.7. Now according to the hanna kit there is an error of 2ppm or 5% which this clearly does not meet.

Did I waste my money on the Hanna test? Is there that much difference between lots of reagent? Maybe I just got a bad lot, do they vary that much? Tanks has been up and running for 13 years and nitrates have always been 30-40, so not looking to change that. Wondering if I should keep spending money on Hanna.

 

[Court_Appointed_Hypeman]

Are these tests really accurate?

Background. Some months ago, I bought the egg because I got tired of guessing on red sea/salifert tests. Results on the hanna were 30-40. That is about normal for this tank. After the initial reagents ran out, i replenished and the next batch of reagents were noticeably higher. I am guessing like 15%.

I purchased a new batch of reagents and just tested both. New reagent was 47.7, the last suspect lot was 56.7. Now according to the hanna kit there is an error of 2ppm or 5% which this clearly does not meet.

Did I waste my money on the Hanna test? Is there that much difference between lots of reagent? Maybe I just got a bad lot, do they vary that much? Tanks has been up and running for 13 years and nitrates have always been 30-40, so not looking to change that. Wondering if I should keep spending money on Hanna.

I know moisture introduced to nitrate test reagents can make them read low, or at least some of the non hannah ones, nyos in my experience if the powdered reagent ever gets any moisture the results for the rest of the batch skew 50% down.

It might be something like that.

I know the hannah alk will read low if its reagent is allowed to evaporate at all

 

[Dan_P]

Are these tests really accurate?

Background. Some months ago, I bought the egg because I got tired of guessing on red sea/salifert tests. Results on the hanna were 30-40. That is about normal for this tank. After the initial reagents ran out, i replenished and the next batch of reagents were noticeably higher. I am guessing like 15%.

I purchased a new batch of reagents and just tested both. New reagent was 47.7, the last suspect lot was 56.7. Now according to the hanna kit there is an error of 2ppm or 5% which this clearly does not meet.

Did I waste my money on the Hanna test? Is there that much difference between lots of reagent? Maybe I just got a bad lot, do they vary that much? Tanks has been up and running for 13 years and nitrates have always been 30-40, so not looking to change that. Wondering if I should keep spending money on Hanna.

The error in the Hanna Checker is 2 ppm PLUS 5% of the reading. For a 50 ppm reading 5% is 2.5 ppm, giving the total error of 4.5 ppm. That puts the two readings in spitting distance of each other.