Thanks, Erik, You've put it well. sh --- Erik Olson <erik@thekrib.com> wrote: > > If you start from the concept that KH and CO2 are > independent of each > other, but help determine pH of the water, you can get > everywhere else > from there, including Red Sea's somewhat misleading > statements. > > Lower KH -> lower pH > Higher KH -> higher pH > Lower CO2 -> higher pH > Higher CO2-> lower pH > > But as Roger noted, increasing KH doesn't really induce > an "ability to > absorb more CO2", just means that if you're shooting for > a particular > desired pH, it will take more CO2 to do so than at a > lower KH. But you > would have to physically crank up the injection rate to > keep the same pH. > > Now, if the KH is ridiculously low (like < 1 degree > sometimes in our water > here in Seattle), then there is so little buffering > capacity that the pH > tends to swing kinda wildly with the amount of CO2 (as > well as other acids > and bases from the fish waste). But of course, at that > KH, the water is > already below 7.0 when it comes out of the tap, not > particularly good for > plants. I *have* to add calcium and mag carbonate just > to keep things > stable. ===== See you in Dallas at the Aquatic Gardeners Associaton 2003 Annual Convention Nov 14-16 S. Hieber __________________________________ Do you Yahoo!? Protect your identity with Yahoo! Mail AddressGuard http://antispam.yahoo.com/whatsnewfree ------------------ To unsubscribe from this list, please send mail to majordomo@thekrib.com with "Unsubscribe aga-member" in the body of the message. Archives of this list can be found at http://lists.thekrib.com/aga-member/