Po4 mixing ratio needed

[Reefpro]

Hi RAndy could you provide a recipes to mix up phosphate for me . I am using food grade trisodium phodphate that states is 99.9%. My tank is 150 gallons and the current level pure my Triton test results is .0173. I am trying to raise to .05

Thanks in advance

 

[Randy Holmes-Farley Verified Community Expert]

Use this calculator and the entry for potassium phosphate. Exact dose won't matter since much of it will bind to rock and sand and that cannot be calculated in advance, but technically you would use 77% of the calculated amount since sodium weighs less than potassium.

James' Planted Tank - Dosing Calculator

 

[Reefpro]

Use this calculator and the entry for potassium phosphate. Exact dose won't matter since much of it will bind to rock and sand and that cannot be calculated in advance, but technically you would use 77% of the calculated amount since sodium weighs less than potassium.

James' Planted Tank - Dosing Calculator

 

[Reefpro]

So the math I’ve done based on calculations is 1 gram of trisodium phosphate added to 25 ml water. 1 ml of mixed solution will raise po4 by .05. Can you confirm ?

 

[Randy Holmes-Farley Verified Community Expert]

So the math I’ve done based on calculations is 1 gram of trisodium phosphate added to 25 ml water. 1 ml of mixed solution will raise po4 by .05. Can you confirm ?

Before the correction of 0.77,yes.
Of course, the effect you observe will be smaller. Often zero for a while.

 

[14 foot reef]

Before the correction of 0.77,yes.
Of course, the effect you observe will be smaller. Often zero for a while.

Randy with this process you mention a considerable amount will bind to substrate and rock, does it ever become an issue of releasing back into the water column after time ( Leaching back into water )

 

[Randy Holmes-Farley Verified Community Expert]

Randy with this process you mention a considerable amount will bind to substrate and rock, does it ever become an issue of releasing back into the water column after time ( Leaching back into water )

Not that you can do anything about. The amount bound is a function of the amount in the water. If you saturated the rock in 0.1 ppm phosphate water for a few days, then tried to lower the phosphate to 0.05 ppm, some will come off. If you try to raise it to 0.15 ppm, more will bind. This may partly be why algae and cyano likes to grow on rock and sand surfaces, as it may locally lower the pH and free some of the phosphate.

pH has some effect as well, and if you suddenly lower or raise the pH substantially, even locally on the rock surface, you can alter the amount bound.