Bob I suspect- though I don't know for sure is that the precipitate occurs because of the low pH of the unmixed solution when the two compounds are in close contact- once either compound is dissolved then the pH would be higher (in the acid range). Cory >that you get CaCO3 as a precipitate when you mix your two salts >simutaneously, but not when you do it separately. Someday maybe I'll try it >just to see. > >Bob > > >------------------------------------------------------------------------- >This is the apistogramma mailing list, apisto@majordomo.pobox.com. >For instructions on how to subscribe or unsubscribe or get help, >email apisto-request@majordomo.pobox.com. >Search http://altavista.digital.com for "Apistogramma Mailing List Archives"! > ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@majordomo.pobox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@majordomo.pobox.com. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!