I bought Hanna alkalinity checker for easier water testing but my alkalinity would always be low at around 6dkh range, so I decided to get Salifert and API ( I know these are not 100% accurate) and surprisingly Salifert was at 12dkh and and API was about the same and retesting with Hanna checker always was low in the 6 range. Well I decided to get new reagent just to make sure even through this was brand new kit with reagent not expiring for next 5 months.
With the new reagent Hanna checker was reading same as the other tests. So maybe there was some bad batch as I saw couple of other threads regarding low alk reading.
Anyway I had friend over bring his spin tester and it was reading about 1dkh lower than these tests. So I decided to get Alkalinity Standard solution which is 250ppm about 13.976dkh
My Salifert test kit was showing around 0.5dkh difference but this could be user error or just test kit accuracy. Hanna checker came right at 14dkh which is within 0.024dkh where Hanna rounds up the number. So I guess if I get new reagent I will test it with the standard solution to make sure it is measuring correctly.
Note: When I do test I add actual 10ml to the cuvette and it always ends up about 1ml higher then the line. I don't think those 10ml lines are very accurate.
With the new reagent Hanna checker was reading same as the other tests. So maybe there was some bad batch as I saw couple of other threads regarding low alk reading.
Anyway I had friend over bring his spin tester and it was reading about 1dkh lower than these tests. So I decided to get Alkalinity Standard solution which is 250ppm about 13.976dkh
My Salifert test kit was showing around 0.5dkh difference but this could be user error or just test kit accuracy. Hanna checker came right at 14dkh which is within 0.024dkh where Hanna rounds up the number. So I guess if I get new reagent I will test it with the standard solution to make sure it is measuring correctly.
Note: When I do test I add actual 10ml to the cuvette and it always ends up about 1ml higher then the line. I don't think those 10ml lines are very accurate.