I have seen that stuff before but never thought of its use in a reactor. First issue is would this be true "magnesium calcite" . This stuff is the most soluble of the carbonates. Quite often it is the stuff the precips out on carbonate gravel as surface precip. This stuff is not true "magnesium calcite" IMHO, as you rarely find rock deposits of it as geologic events alter it.
I have tried to beat this into people heads on our chem forum, even Randy. They can't get it out of their head and the same for SeaChem Magnesium maybe, that Magnesium Calcite IS NOT Dolomite ( which is often gray). And I will bet an arm and a leg this SeaChem stuff is Dolomite/Dolostone or a variant and not Magnesium Calcite. Why ? It is not found in big quantities, it is a surface coating most of the time. There are some deposits from ooides and some shells that are made of magnesium calcite (meaning sitting on the ocean floor not rocks yet. And then there are speleothem formations (caves). Some dolomites, limestone's etc. have magnesium calcite in them if not fully altered
However, the do say this
However, magnesium calcite, such as our Gray Coastâ„¢, has been shown to have a higher buffer capacity than even aragonite, making it an ideal choice for marine aquaria.
Which does make it sound like the real stuff. But since so many people equate Magnesium Calcite = Dolomite....I wonder if they are being honest. I would like to see an XRD on it, the only true proof
An ssay does not tell you it is magnesium calcite.
But for us it is to high in Mg.
If anyone is really interested in the true carbonate world in terms of the chemistry of limestone, aragonite, magnesium calcite, dolomite , etc..The single best ref in the world is
Carbonate Sedimentology by Tucker
and it is sitting on my lap :lol: