White precipate dosing Randy's Alkalinity Recipe # 1

[iTread]

Hi, as the title says, I am getting a white precipitate (white flakes floating around) when dosing Randy's Alk recipe # 1.
I have read some of the threads on this but still confused.
I make my alk using Arm and Hammer by baking it for an hour.
Here is the catch, sometimes I get the precipate and sometimes I do not. It depends on which batch I am dosing.
Yesterday I dumped about 20 ml in from one batch and got the flakes. Right after, just to test, I dumped some of the other batch and there were no flakes.
What could I be doing wrong? Am I doing something wrong when I make the recipe? I believe I do it the same every time.

 

[Randy Holmes-Farley Verified Community Expert]

It is normal get a precipitate of magnesium hydroxide with high pH additives. that will redissolve. You can reduce it but diluting the product, adding it more slowly, and to a higher turbulence area.

in some cases you may also get a slower to form calcium carbonate precipitate that won’t dissolve. Same advice above relates to preventing it.

 

[iTread]

Ok. But why would one solution cause it and other not? Theoretically they are both the same thing since I follow the same recipte. As I mentioned, I did two different batches at the same time and one caused flaking and the other did not. Could there be something that I am doing incorrectly with the recipes?

 

[Randy Holmes-Farley Verified Community Expert]

Ok. But why would one solution cause it and other not? Theoretically they are both the same thing since I follow the same recipte. As I mentioned, I did two different batches at the same time and one caused flaking and the other did not. Could there be something that I am doing incorrectly with the recipes?

I'm sure something is different, but cannot know what since you say its the same. Extent of baking, pouring rate, concentration, tank temp, tank pH before addition, tank flow, magnesium levels in the water, etc. all play a role.