In this article
Product Review - My Dialyseas Saga: Pros and Cons by Ken Feldman - Reefkeeping.com it states " I don't have a value for the K
sp of CaCO
3 at
pH = 7.0; Holmes-Farley supplies one for
aragonite at
pH = 8.2, natural seawater: K
sp = 6.5 x 10
-7 M
2/L
2 at 25°C. (Holmes-Farley, 2002)." This
Advanced Aquarist's Online Magazine - Chemistry and the Aquarium: Calcium is the referenced article.
My understanding is that at
pH 8.2
aragonite is soluble and able to provide buffering. At a
pH of about 7.7 the
aragonite (chemically it is CaCO3) begins to dissolve or break into its component elements. At a
pH of about 6.7 like you would have in a calcium reactor becomes quite effective at raising
Ca levels in your tank.
