Another thing I try to do is to always insert the vial into the tester in the same orientation - with the "10ml" printing facing forward. That way if there is a smudge on the glass, it'll be the same smudge during the calibration reading (before adding the reagent) and the final reading.I’ve found that the vials for the Hannah test can give high readings if they are not perfectly clean. I always rinse the vials out with ro after each test. Each time I test I rinse the outside with ro and wipe dry with a microfiber cloth.
Are you sure that's the ULR checker? Mine says ULR after the word Phosphate
Correct. The Ultra Low Range will have ULR on it. He has the Low Range Po4 checker.Are you sure that's the ULR checker? Mine says ULR after the word Phosphate
For those vials that the wording has disappeared I drew a small arrow with a sharpie on the cap. Also don't trust the 10ml mark on those vials as they are notoriously wrong. Always use a 10ml syringe.Another thing I try to do is to always insert the vial into the tester in the same orientation - with the "10ml" printing facing forward. That way if there is a smudge on the glass, it'll be the same smudge during the calibration reading (before adding the reagent) and the final reading.
Not as far as I can tellany difference in coloring or appearance