precipitating sodium bicarb?

[Stones]

I found I had the same problem when dosing sodium carbonate. No matter how little I dosed in the sump, I would always end up with load of precipitate.

I found that dosing sodium bicarbonate worked much better although it did end up lowering the pH somewhat. Dosing sodium carbonate, I couldn't keep my alk levels above 7 without execessive precipitation. Dosing sodium bicarbonate, I was able to get my alk as high as 12 without any precipitation.