|Byron ||08-29-2010 06:58 PM |
As others have mentioned, I also do not recommend "buffers." Adding any chemical or substance to an aquarium is something I never do unless it is essential, such as water conditioner and plant fertilizer.
There are ways to naturally buffer your water and it will be stable, without having to constantly add chemicals. First it is important to understand the reason behind all this; if this is "old news" just skip over it, but as I do not know your level of understanding I will explain it briefly.
The hardness (both GH and KH) and the pH are connected. In nature, acidic waters are usually soft while basic (alkaline) waters are usually hard. Hardness is the measure of dissolved minerals and salts in the water. In hard water, containing more minerals and salts, the acidics and organics are bound to the minerals, removing them from the water; the pH remains basic. In soft water with few or no minerals, the acids and organics remain and the pH will lower as they increase. In cases where certain minerals or salts that do not naturally bind with organics are added to tap water, the pH can be low even if the water is hard. The same occurs when acidic substances such as CO2 are added to the water, because this can be stronger than the effect of the minerals and salts in the water.
In the aquarium as acidics (organics) are produced by fish and biological processes the pH will tend to fall. But the hardness will counter this as described above. The carbonate hardness (expressed as KH) acts as a buffer on the pH. If the tap water parameters are basically what you want in the aquarium, regular (weekly) partial water changes of 40-60% will usually serve to maintain this. However, the KH of the water needs to be sufficient to do this or even during a week the pH can fall due to normal acidification.
The best way to "buffer" the pH is naturally, by adding minerals (chiefly calcium and magnesium). But this will raise hardness and correspondingly the pH, and this may not suit the fish. If on the other hand you want to lower the pH of the tap water for the aquarium, the best natural method is by mixing tap water with "pure" waster such as RO (reverse osmosis), rainwater or distilled water. All of this can have critical implications in an aquarium. I can perhaps go into this more once I know your tap water parameters and where you want the aquarium water parameters in relation to that.