How common is it for a Hanna phosphorous test to have bad reagents?

[BriDroid]

I bought some new reagent for my ULR Phosphorous checker a two weeks ago. I've been battling low PO4, so multiple tests coming back as 0 didn't raise much of an alarm at first. I've been dosing NeoPhos and retesting daily. Every time it would read 0. Today I tested and got a 0, then dosed enough NeoPhos to raise it to 0.05ppm. After about 4-5 hours I tested again. I should have been somewhere around 13ppb on the checker, but sure enough it was 0 again? I'm thinking I have some bad reagent? I reached out to Hanna and they are going to send me some different lots of reagents to try. I don't think it's the checker, since the old reagent was giving me readings.

Is this a common thing for the Hanna reagents to go bad? This box was bought from a LFS and the expiration date is good?

 

[Patx]

Have you try to put drop of neophos in your test ?

New tank ?
New dry rock ?

 

[rtparty]

With enough demand, you could be eating through that PO4 shortly after it is dosed.

You are also at the very bottom of the the range and it gets hard to test that low. Pull out some tank water, dose it up to .1ppm, and test that. Test more than the margin of error for sure

 

[dangles]

Dude! I’m having the same problem!!

The thought crossed my mind that it might be bad reagent but I blew it off as not likely. Maybe there’s something to it because I didn’t start getting zeros until sometime after I started a new box of reagent!

I’ll have to reach out to them as well.

 

[dangles]

You mean phosphate right?

I guess you did say ULR. Mine is just the standard LR one.

 

[vadryn]

FWIW - I store my vials with RO Water in the Hanna case to try and prevent any staining, and had problems with my Nitrate reagent in particular until I stopped storing the reagent packets in the case. Once I kept them separate the problem went away.

 

[SliceGolfer]

From this thread it would appear your tank is two months old. Very normal for phosphate to be depleted quickly, binding to rock and sand, requiring multiple doses. I’ve been using the Hanna phosphorus test kit for 5+ years and have never come across a bad reagent.

Add enough Neophos to register 0.10 on your test kit and then you can monitor how long that dose will last. I dose DIY trisodium phosphate daily and require maintenance doses of 1ml in my 15g tanks, 5ml in my 40g tank.

 

[BriDroid]

You mean phosphate right?

I guess you did say ULR. Mine is just the standard LR one.

Mine is the ULR Phosphorus test in ppb. You have to use the chart, or math, to get phosphate in ppm.

 

[BriDroid]

FWIW - I store my vials with RO Water in the Hanna case to try and prevent any staining, and had problems with my Nitrate reagent in particular until I stopped storing the reagent packets in the case. Once I kept them separate the problem went away.

I have been storing them with RO/DI water in the Hanna case too. I saw that on BRS TV. Maybe I need to stop doing that?