Yes, Frank. Some folks coral (skeletons) for carbonate. A slight "problem" with coral as a form of carbonate is that you can get more abrupt changes every time you do a big water change until the enough enugh of the coral "melts" to bring the pH back to the target zone -- until the next water change. With baking soda you can contro the pH as you add water. Not to mention coral is not as easy to control if it's not in a nice granular or powder form. The less finely ground it is the slower it dissolves. So the pH drops when you do the water change and then the pH is brought up very slowy as the coral "melts." With powder you just measure and you know exactly what will happen to the water. If you're concerned about just adding water and powder directly to the aquarium, you can add the water to buckets, add powder, and then put it in the tank. Or, as the water is being added, add a little bit of pwder, then a bit more -- paced out over the time it takes to refill the aquarium. This works really well with baking soda because it dissolves readily and you're immediately controlling the pH as the water enters rather than waiting for the powder, or granules, or coral pieces to dissolve. Any form of calcium carbonate "melts" much slower than baking soda, so you have less short term control of the pH. Although you're fish and plants probably won't give a darn either way. I've never seen any adverse reaction from just adding the soda when adding the water and I've done it on 15 gallonand 30 gallon tanks as well as much larger ones -- even with cardinals and other so-called pH-delicate fish. Baking soda won't raise the GH. It only raises the KH. Calcium carbonate raises both. Crushed coral, if ground finely, will dissolve faster than coarsely crushed, crunched or whole piece/chips coral. Corals (technically the dried skeletal structures thereof)*are* calcium carbonate and you can buy raw calcium carbonate from a number of sources cheaper as a plain chem than in the form of crushed coral in lfss. Coral Calcium is sometimes known by the less respectiful term, overpriced calcium carbonate ;-) You can pick up Potassiumm (K2SO4), Nitrate (KNO3) and phosphate (KH2PO4) while you're ordering from litemanu.com and have everything but the trace nutrients for plants all taken care of for years. But I take back that you can get calcium carbonate from Liteman.com. I just checked. But you can get it here: http://www.ebrew.com/wine/winemaking_acids.htm#CAL a pound for $3 plus shipping. And yes, a pound lasts a long long time. And, as I said, you can get baking soda from just about any store that sells grocery type goods. Even 7-11 :-) sh --- WB4CIW@aol.com wrote: > While you can raise the KH & GH by using Baking Soda, I'm > concerned > about the abruptness of the change that could result, and > the possible > "yo-yoing" of the water's chemistries. > In my 30 gallon tank, to raise my KH & GH, I simply went > to the local > fish store and purchased a 2 pound bag of crushed coral. > > I have, literally, two pinches of the coral in my filter > on the return side > so the returning water passes through it. > It raised my GH & KH slowly to where I want it, and as > the coral > dissolves, I replace it a pinch at a time. In over 5 > years, I still have > over a pound and a half remaining. ===== S. Hieber - - - - - - - - Aquascaping by Takashi Amano and more at the AGA 2004 Annual Convention Nov 12, 13 & 14; Marriott Crystal Gateway, Arlington, Virginia, USA Aquatic Gardeners Association www.aquatic-gardeners.org __________________________________ Do you Yahoo!? Yahoo! Small Business $15K Web Design Giveaway http://promotions.yahoo.com/design_giveaway/ ------------------ 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/