Can something cause false Phosphate?

[jasonrusso]

I have a 34 gallon Red Sea C-130. I test with a Hanna ULR phosphorus tester. For years, my Phosphates have been in line (0.02 to 0.1). Recently, the Phosphates have been 0.3, 0.4 etc. I haven't really changed anything feeding wise. I run Seagel in a reactor with a scoop of phosguard. This hasn't made any difference.

The only thing I changed was that I started running a Sulfur reactor for nitrate. Is it possible that the Phosphate and nitrate was in balance and was being consumed. Now I dropped the nitrate so there is excess Phosphate?

 

[Biglew11]

What is your nitrate level now?

The bacteria feed on nitrate and phosphates if one is bottomed out to 0 the other can rise.

I think that phosphates can bind to the testing vial. You could test this by making a batch of fresh saltwater and test it for phosphate. You can clean them periodically with vinegar,

 

[Reef.]

What is your nitrate level now?

The bacteria feed on nitrate and phosphates if one is bottomed out to 0 the other can rise.

I think that phosphates can bind to the testing vial. You could test this by making a batch of fresh saltwater and test it for phosphate. You can clean them periodically with vinegar,

Rodi and or the salt can have PO4, I’ve tried this and got readings from freshly mixed salt.

 

[Biglew11]

Rodi and or the salt can have PO4, I’ve tried this and got readings from freshly mixed salt.

+1 True, I have a hard time keeping phosphates so kind of forgot this can be an issue. you can still take a vial you know is clean and test for phosphates here as it can be a source.