RichToyBox wrote, On 30/07/2007 13:52:
There is another test out there that is more beneficial, called KH
hardness.
The KH test measures the bicarbonates in the water. If the bicarbonates
drop low, then the pH becomes unstable and will crash to very low numbers.
The bacteria use bicarbonates in there changing ammonia to nitrite, and
nitrite to nitrate. The bacteria actualy produce acids that must be
neutrallized for their health and the health of the fish. The bicarbonate
ion is easily changed by the acid to CO2 and water. It can also neutralize
the hydroxyl (very alkaline) ion, by being converted to water and carbonate
ion. The carbonate ion will combine with the calcium in the system and make
a relatively insoluble balance limestone like material. The KH needs to
stay above 80, and it doesn't hurt a thing to have it stay above 300. The
balance between bicarbonates and carbonates occurs at a pH of 8.3 to 8.4.
To raise the KH add baking soda.

Would acid in the water act on chalk in the same way? Could a lump of
chalk be used as a slow release aid to buffering?


--
DavidM
www.djmorgan.org.uk