Phosphorus vs phosphate

[Guy714]

My ICM test is showing elevated phosphorus but no phosphate. What’s the difference between the two and how can I fix the problem? I appreciate all input.

 

[Dkeller_nc]

If you mean an "ICP test", realize that ICP quantitates elements (e.g., Carbon, Nitrogen, Phosphorus, Zinc, etc...), not compounds. And in a reef tank environment, most of the phosphorus would be in the form of inorganic phosphates and organic compounds that include phosphorus as part of their structure.

 

[Zach W]

To convert It’s just the ratio of molecular mass of PO4 to P. PO4 weighs 95g/mol and P weighs 31g/mol. So you multiply your P level by 3.066 to get your PO4 levels

 

[Zach W]

And if its reported in ppb your conversion will give you your PO4 level in ppb. If you want to get to ppm you just multiply by 1000.

 

[Randy Holmes-Farley Verified Community Expert]

My ICM test is showing elevated phosphorus but no phosphate. What’s the difference between the two and how can I fix the problem? I appreciate all input.

Can you tell us exactly what you got and from who?

Those two tests are done differently and detect different things, but generally the explanation lies in interpretation, not in having only forms of phosphorus that are not detectable as phosphate.

 

[Guy714]

Hi Randy,

It's from the same ICP ATI test. I'm attaching a screenshot. I'm confused to whether I should add phosphate to my tank?

 

[Marty's Reef]

Hi Randy,

It's from the same ICP ATI test. I'm attaching a screenshot. I'm confused to whether I should add phosphate to my tank?

Did you ever get any kind of explanation about this? I ask as I am showing something similar on my ICP Test.
Thanks.

 

[Randy Holmes-Farley Verified Community Expert]

Did you ever get any kind of explanation about this? I ask as I am showing something similar on my ICP Test.
Thanks.

WHat is the concern?

ICP measures phosphorus, and they just multiply up the value to get the value as if it was all phosphate.

 

[Marty's Reef]

Actually after some more reading I now understand it is the same values just expressed in different fashions. Guess they make it a little confusing by giving both. Lol

 

[Randy Holmes-Farley Verified Community Expert]

Actually after some more reading I now understand it is the same values just expressed in different fashions. Guess they make it a little confusing by giving both. Lol

I originally thought they actually measured both, which would be much more interesting.

 

[Marty's Reef]

I originally thought they actually measured both, which would be much more interesting.

ya I assumed it was 2 different things. Like I don’t need 2 different Hanna checkers to tell me the same thing.