Hanna ULR and Phosphate Checker

[Reef This]

I'm having kind of an issue..

Checking Phosphates, the ULR checker reads 54 and 49 in the 2 tests I did. Which when converted from Phosphorus to Phosphate is about .15ppm and .13ppm, respectively.

When I use the normal Phosphate Checker, 2 different tests, it read .04ppm and .05ppm.

Even with the +/- buffer Hanna specs list for accuracy, something doesn't add up.

I don't have an algae problem at all, but I do test for phosphate anyway. I'm a little confused by these results. Can anyone help me make sense of this?

 

[Uncle99]

I find the measurements of phosphates to have been my biggest challenge in this hobby.
I have used every test kit available and an ICP and got everything from 0.3-.25.

So now I just use my cheap Salifert test kit and if I can see barely the lightest of blue, (0.00-.2) we’re good to go. I would only look further if I see algae growth or my corals look unhappy.

Hobby grade test kits results show more flux when the thing your testing is only a tiny trace amount like phosphates, or, that the sample size is itself very small like the Hanna Checker.

Both your results seem fine to me.

 

[RioReefr]

I will chime in as I also have the same HI Phosphate Checker. My results are pretty similar with results ranging in the 40's. The water turns a light blue color.

I have tried to reach out to Hanna Instruments customer service -- which honestly has been awful. The people say they don't know. They gave some guy "Chris" who was supposed to be the "expert". I sent him 2 emails, neither of which I got a response.

I am very disgusted because this is a new tank (only 3 weeks old) and have no idea if my phosphates are high or not. Its a new tank with live-rock pulled out of very established tank and I feed extremely little. My phosphates should be lower than what the HI Checker shows, but since they refuse to response or answer me, I have no idea.

Big Thumbs down on HI Customer Service. (And please don't blame Covid, so sick of that excuse for poor Customer Service from companies!)

 

[Kriegad]

Did you make sure your reagents / test kits aren’t expired

 

[tswizzle]

phosphates are tricky..i've used the ULR checker and gotten different results 2min after using the same samples. their site says even smallest smudges or scratches on the glass can alter readings based on reflections

 

[RioReefr]

Just an update, I gave up on HI Customer Service. Live-chat, people don't know and they do not respond to emails !!!

Anyway, I went out and got some GFO and let it in a high flow area. (I dont have a reactor). I got my HI Phosphate ULR down to 0.18 and has been staying in the low 20's. The color almost nothing, perhaps just slight blue-tint.

BTW, I purchased everything back in December 2019 including their "Standardized Calibration Kit".

I suspect that 0.18 PPM and that water barely changes color is a good indication my Phosphates are near 0. I see very little glass algae and just now my huge Devil's Leather Coral is showing polyp extension.

I am not bashing Hanna Instruments -- they do sell quality products. But clearly due to Covid, they must have completely laid-off their Customer Service staff.

My advice to other, if you get a very slightly blue tint then you probably don't even need the Checker. Just use the reagent, shake well for 2 minutes, let it stand for 3 minutes. If you don't see any blue, you are probably good to go.

BTW, HI is advestising a Nitrate Checker but when I inquired about ETA they told me "in 2021" LMAO. Not sure why they would even put it on their site and say Soon To Come.