Phosphate dosing not showing on tests

[Jungle321]

Hi everyone, I have been struggling with non detectable phosphate levels for a while now and I have decided to try out phosphate dosing. I have seen no results despite constant dosing so I have decided to add the phosphate liquid directly into the tested sample and Salifert and API tests still show 0. Is that supposed to happen or should I try a different brand? Currently I'm using ME coral phosphate supplement that uses Sodium phosphate and Potassium phosphate in 10,000 mg/l concentration.

 

[Reefing_addiction]

Are you sure your testers are good?

I used neophos to get my phosphates up. And it took a while. Remember that anything I. Your tank that uses phosphates will eat up the phosphates you add. How long after adding to the tank do you test?

A Quick Look say 2drops raises phosphates by .01 in 100l. So you would need 6 drops to raise it to .03

How new it the tank?

Your rocks may be absorbing all the phosphate you add or if you have micro algae it may be sucking it up.

try adding 2 drops to 10ml of RODI and test that per Salifrets instructions.

Or switch to NeoPhos

 

[Jungle321]

How new it the tank?

Your rocks may be absorbing all the phosphate you add or if you have micro algae it may be sucking it up.

try adding 2 drops to 10ml of RODI and test that per Salifrets instructions.

Or switch to NeoPhos

The tank is almost 4 years old at this point and I always struggled with keeping the nutrients detectable in this system. I have also already tried adding 2 drops to 10ml of RODI and testing that yields results of 0ppm with Salifert tests. I wonder if my lfs sold me faulty product....

 

[aSaltyKlown]

Double or triple the dose. I dose Trisodium Sulfate and had to do this to get a reading. The next day it was back to 0. I tripled my dose for a couple days and then doubled my dose daily for over a week, before it became stable enough to only dose twice a week. It is binding to the rock and sand and being used by the animals/plants in the tank.

As far as your tester, I would think it would show something adding it directly to the test sample. Could be it's still not enough with the +/- of accuracy. I like Hanna checkers for PO4.

 

[Randy Holmes-Farley Verified Community Expert]

I don’t know why it doesn’t show up in an out of tank test.