Hanna ulr phosphate tes kit

[Guerra]

Hi
Need help with my hanna checker ulr phosphate kit since i bought this test never got the same result i have been doing step by step after a lot of research and still gives me different result:(

 

[jwshiver]

Different results back to back? How much of a difference? Are you wiping off finger prints from the cuvette? Are you placing the cuvette in the checker the same way each time? I place mine with the 10 ml facing out every time. Small scratches, finger print smudges, bubbles, etc can give different results.

 

[rob safron]

I have the same issue. One time it can be as high as 30. Repeat the test it’s 2. So for fun I tried this: I used 2 vials. One with tank water, the other with reagent. The first test is always high, sometimes 12 sometimes 30. Then using the same vials I Test over and over several times. The other test always come back very close in the 0-5 range. I have tried this over a few days. My regular Hanna phosphate Test is in the same range as the lower levels, .00-.03. I don’t trust the ULR Test performing one time as directed. I would be at a phosphate of .1 at times if I did. No alge and I clean my glass once a week at most.