New Hanna Alkalinity reagent error

[dede]

I have an older hanna checker alkalinity HI755 that reads in PPM and just ordered the new reagent HI772s to replace the old reagent HI755s.

I have not tested my alkalinity in a while and so ordered new reagent. Well I was shocked to see it gave me a reading of 6.16 dkh after using the conversion x .o56. I tested it multiple times over 2 days and all the same result.

So just to confirm the result I tested with the red sea test kit and got 8.7 dkh results which are quite a difference. I also used some very old reagent I found that expired in 2015 on the Hanna checker and that also gave me a reading of 8.7 dkh.

Anyone else having problems with bad readings with the new replacement reagent HI772s, my lot number is 7309 and exp is 08/2019.

Does the new reagent only work with DKH hanna units or will it work with the PPM units? I did email hanna but wondering what others experiences are.

 

[Larry L]

My understanding was that the same reagent should work in either tester, but you could ask them directly in their sponsor forum: https://www.reef2reef.com/forums/hanna-instruments.941/

 

[Randy Holmes-Farley]

The alkalinity checkers that just read in different units (ppm vs dKH) apparently use the same reagents.