Hanna Nitrate HR is in the house!

[Dan_P]

Wouldn’t this essentially be (if using 50/50) be testing half the nitrates in my tank? Would I take that answer as stone, or multiply it by 2?

Multiply by 2 for a 50:50 diluion.

 

[KenO]

Wouldn’t this essentially be (if using 50/50) be testing half the nitrates in my tank? Would I take that answer as stone, or multiply it by 2?

Yes if you are maxing out the meter then try the 50/50 mix. The result would be half of the true level of NO3. I do this with my Hanna LR phosphate colorimeter. I have SW and FW tanks. The FW needs to have a PO4 of around 3ppm. The meter only goes to 2.5ppm. I cut the FW sample 50/50 using RO/DI water. I then multiply the result by 2.

 

[saltyhog]

Wouldn’t this essentially be (if using 50/50) be testing half the nitrates in my tank? Would I take that answer as stone, or multiply it by 2?

Yes, multiply it by 2 with a 50/50 dilution. Get's a little more difficult if your fresh salt mix has PO4 in it.

 

[KenO]

Yes, multiply it by 2 with a 50/50 dilution. Get's a little more difficult if your fresh salt mix has PO4 in it.

I think you meant NO3 not PO4.
with that said, I'm using the tester to test NO3 in my FW tanks. I made up some known NO3 solutions at 15ppm, 20ppm, etc. I used the tester to test them. The results were close, less than 5%. Some of the error could have been with my solutions. So I think the SW could be cut with RO/DI water and still give fairly accurate readings of NO3. If it was me, I'd cut it with RO/DI water and test.

 

[saltyhog]

I think you meant NO3 not PO4.
with that said, I'm using the tester to test NO3 in my FW tanks. I made up some known NO3 solutions at 15ppm, 20ppm, etc. I used the tester to test them. The results were close, less than 5%. Some of the error could have been with my solutions. So I think the SW could be cut with RO/DI water and still give fairly accurate readings of NO3. If it was me, I'd cut it with RO/DI water and test.

Yes, thanks for the correction.

Interesting. I wouldn't have thought of using it for freshwater applications. I wonder if they even know it works for freshwater too. Since you've documented that it does work , it seems like it would be fine to dilute with RO/DI although it does introduce an additional variable.

 

[gbroadbridge]

Yes, thanks for the correction.

Interesting. I wouldn't have thought of using it for freshwater applications. I wonder if they even know it works for freshwater too. Since you've documented that it does work , it seems like it would be fine to dilute with RO/DI although it does introduce an additional variable.

I asked Hanna support a while ago, and their response was that the device is not qualified for use in fresh water and will give indeterminate results.

It may well work with one tank and give nonsense results on another tank depending on the water chemistry of the tank.

 

[KenO]

I asked Hanna support a while ago, and their response was that the device is not qualified for use in fresh water and will give indeterminate results.

It may well work with one tank and give nonsense results on another tank depending on the water chemistry of the tank.

I made up 6 different NO3 concentrations using RO/DI water. I even let them sit for a few days. The results were consistent from day to day. I've tried it in 2 different FW tanks with different tank conditions. No issues. I even used a FW dosing calculator. I dosed the proper amount of KNO3 to hit a target NO3. The reading was spot on.

 

[gbroadbridge]

I made up 6 different NO3 concentrations using RO/DI water. I even let them sit for a few days. The results were consistent from day to day. I've tried it in 2 different FW tanks with different tank conditions. No issues. I even used a FW dosing calculator. I dosed the proper amount of KNO3 to hit a target NO3. The reading was spot on.

Okay, but what I am saying is that Hanna instruments state the instrument is not qualified for use with freshwater.

Use any results at your own risk as it may vary especially if Hanna decide to change the composition of the reagent.