Salifert & Hanna ULR Phosphate Comparison

[Dan_P]

I bought a Hanna ULR phosphate checker and was curious about how it compared to Salifert which I have used for years. For the head to head comparison, I prepared tank water samples spiked with food grade TSP. The amounts were small, so pH was not impacted (KH2PO4 Would have been a better choice). Both Salifert and Hanna indicated that the tank water phosphate level was below detection before spiking it. Sample concentrations are in the first two columns and test results in the last three columns.

Salifert is good for ballpark numbers and is useful to judge whether you have stripped the system of phosphate when you use a blank to determine whether the test solution is colorless. In my tests, it did not do well with high phosphate. This might have something to do with my using TSP as a reference standard. So, don't bash Salifert on the high end results.

Hanna ULR did well until the lowest phosphate level, overestimating the amount by 10X. Again, don't bash Hanna because the company does tell us about the standard deviation which really becomes important at very low color intensities.

 

[Boomer]

Dan

The Hanna checkers have always faired well in all tests comparisons. The real challenge is their Alk and Ca++. That would be something for you to tackle.

 

[seldin]

I was sick of Salifert testing for Phospates looking at a color chart. I love the Hanna ULR. My only negative is to make sure I do the testing quickly or the timer runs out.

As far as accuracy, BRS has done nice videos on comparisons, etc.

 

[ducati335i]

I use the salifert.. if you use another test tube w water in it,(One w the color and one just plain water) it makes it easier to use the color chart Comparing them, am I making sense?