Hannah ULR phosphate checker accuracy

[Reef.]

A little backstory on my tank, its nutrient deficient. I've always had to dose both phos and nitrate. With that said, my experience with hanna phosphorus testers have not been positive. I notice my alk would go up and my colors bleaching. When testing for phos using the hanna it would often report much much higher levels. My last experience with this was confirmed by an icp test. My hanna reported .5 phos while icp test was near zero. I also understand it takes several weeks for the ICP test to send results, and the sample water chemistry can change in that time. My next step was to compare testing results from two different testers.... A milwaukee 412 and hanna phosphate tester.

Hanna reported .08 phosphate while the milwaukee test resulted in 0. I started dosing more phos to settle the experiment. After a week, i noticed colors starting to return and my alk consumption going up. When testing again with the milwaukee, it resulted in .03 of phosphate, the hanna stated 150ppb which is .4 ppm! FYI i usually purchase calibration cuvettes for hanna and calibrate every 6 months. I did test and according to the calibration, the tester is still good. Needless to say i have retired my hanna. Lesson....listen to your tank....use test to confirm and use ICP test to confirm test.

I don’t think 150ppb is 0.4ppm.

Hanna is very good with PO4, think you have confused yourself with ppm and ppb, also icp on po4 is not accurate, it estimates po4 and it’s total po4 whereas Hanna is free po4. So again the comparison is going to mislead you.

 

[Randy Holmes-Farley]

I don’t think 150ppb is 0.4ppm.

Hanna is very good with PO4, think you have confused yourself with ppm and ppb, also icp on po4 is not accurate, it estimates po4 and it’s total po4 whereas Hanna is free po4. So again the comparison is going to mislead you.

150 ppb phosphorus is approximately 0.46 ppm phosphate.

 

[Reef.]

150 ppb phosphorus is approximately 0.46 ppm phosphate.

Google let me down.

 

[Sdot]

I don’t think 150ppb is 0.4ppm.

Hanna is very good with PO4, think you have confused yourself with ppm and ppb, also icp on po4 is not accurate, it estimates po4 and it’s total po4 whereas Hanna is free po4. So again the comparison is going to mislead you.

Thanks... but im not confused...although i did mention ppm as ppb... fact still remains the hanna was off for me and relying on it caused my animals to suffer. Im using the tools that will lead to my success... the Hannah phosphorus checker will not be in my arsenal. Also im not looking for complete accuracy... i think thats a fools errand in this hobby with current test kits, however precision is something that we do rely on... the Hannah has let me down in that regard.