Hanna Ulr phosphate checker bad reagent?

[Coralville]

Anyone having suspicious results from their Hanna phosphate checker? I tested my parameters the same day I sent a sample off to Triton.

Triton po4 0.015

My po4 results 0.095 lot#H063
0.092 lot#H071

I checked it twice with 2 different lots of the reagent since I don’t usually have po4 this high. So the correct result is most likely Triton? @Randy Holmes-Farley ? I am having issues with my skimmer at the moment, so it is possible my phosphate levels have gone up. Don’t know which result to believe.

Btw last year the triton results were 0.029 for po4 and the Hanna checker was 0.04, so very close.

 

[Coralville]

My Triton results are attached

 

[Randy Holmes-Farley]

I wouldn't overly rely on assumptions about how well those two need to agree, unless it was a single sample split in half, and even then, the ICP sample likely sat around for a substantial period before testing, which may allow microbial processes in the vial to alter the results.

 

[Coralville]

Ok, thank you!