which method or test kit i should use to measure po4 for freshly mixed salt?

[David Cher]

which method or test kit i should use to measure po4 for freshly mixed salt?

i used hi736 to measure the po4 fm salt and made sure that it is fully dissolve . it is reading at 25 ppb

did i do something wrong ?

the tds of the RODI is 0 and 0 on the hi736

 

[Ron Reefman]

Testing error?
TDS error?

To be honest, in 20 years I've never tested new saltwater for anything but Ca and alk. And that was just because I switched from IO to IO Reef Crystals.

 

[David Cher]

Testing error?
TDS error?

To be honest, in 20 years I've never tested new saltwater for anything but Ca and alk. And that was just because I switched from IO to IO Reef Crystals.

i just changed to a new HM inline reader

 

[David Cher]

any other idea or test kit that i should use ?

 

[Pistol Peet]

I wouldn't think there should be any need for testing in freshly mixed saltwater

 

[David Cher]

if the purpose of the water change is to lower po4 , you do not measure the incoming water, how to know whether does it work or not ?

 

[Pistol Peet]

if the purpose of the water change is to lower po4 , you do not measure the incoming water, how to know whether does it work or not ?

Po4 is phosphorus and shouldn't have this in the new saltwater mix this is why it lowers it when you switch out the water

 

[Jeffcb]

Just use Red Sea.

 

[David Cher]

Po4 is phosphorus and shouldn't have this in the new saltwater mix this is why it lowers it when you switch out the water

here is the problem .

i measured my tank water before changing and after change , there is a 20ppb increase
what do you think ?

 

[Pistol Peet]

here is the problem .

i measured my tank water before changing and after change , there is a 20ppb increase
what do you think ?

The only thing I could think of is there is maybe phosphorus in the kind of salt mix you use what brand is salt mix are you using do they use 100% pharmaceutical grade materials