a little confused about buffers

[sepope]

Is alkalinity and carbonate hardness the same thing? Or are they different- one a buffer for PH and the other for calcium???

[asiankidd2]

ph and calcium although different are closely related, in the fact that calcium is needed to maintain higher levels of ph. When you add a bu ffer it helps to bring those parameters to those spec, i currently am fighting a ph issue since my ph is only at 8.0 and i want to raiise it to 8.2 i added dkh buffer from kent, but with little success i tested my calcium and noticed it was way low which i later found out that was the reason my ph is so low, then i used kents liquid reactor calcium buffer which helps bring calcium back up to normal levels hope that helps between the 2 just test for both and add accordingly shoot for a calcium of around 400-450ppm oh and btw alkalinity is a measure of ph, being acidic at lower ph, neutral at 7, and alkaline at higher ph make sense?

[MCary]

Buffering is the ability of the water to maintain a pH. The test kits you have use a technique where acid is added to the water until it reaches a certain pH (4.5 I think) and turns an indicator a different color. So if you have 2 solutions both with an pH of 8 and one turns after adding a couple drops and the second takes 10 drops then the second is more resistant to pH changes and thus has a higher buffering ability. Most of the buffering ability is due to the presence of bicarb or carbonate so it is called carbonate hardness. Alk and carbonate hardness are not the same thing but often used interchangably.

[angelces]

an article about ph buffering
http://www.reefkeeping.com/issues/2005-02/rhf/index.php

[Spuds725]

Here is an excellent article on the calcium alkalinity relationship--

http://www.advancedaquarist.com/issues/nov2002/chem.htm