white precipitation residue from Trisodium Phosphate dosing

[rowenaad]

Hi, today i dosed a few drops of Trisodium Phosphate solution and noticed it became some white flake-like residue floating all around the tank. Im pretty sure it did not happen the last time i used that solution. Is this normal? TIA

 

[Dan_P]

Hi, today i dosed a few drops of Trisodium Phosphate solution and noticed it became some white flake-like residue floating all around the tank. Im pretty sure it did not happen the last time i used that solution. Is this normal? TIA

I think the phosphate solution is too concentrated. The precipitate could be magnesium hydroxide from the high pH of the phosphate solution, or calcium phosphate, or both plus others.

 

[Randy Holmes-Farley Verified Community Expert]

I agree. Dilute it more and add to a high flow area away from corals. It is a high pH solution so some precipitation of magnesium hydroxide may happen, but it should redissolve. You want to mix it in before calcium phosphate forms. A little vinegar mixed with it may also work.