[AshK]

I have collected the necessary components for pressurized CO2 but I am reluctant to install it until I learn more about pH swings and such. I just bought a GH and KH test kit and want to learn what are acceptable levels and what to watch out for. I've googled and such, but I know there is a lot of garbage out there. Anyone have a couple of good links?

I guess I'm just looking for a huge tl;dr wall of text crammed full of info. I would like to read more than I would ever need to know just to cover all bases.

 

[trenac]

It is best to try keeping your KH at least 3 or better when injecting C02. However mine usually sets at about 2, which I've never had a problem with. Your GH will always/should be higher then your KH.

Here is a good link to help you out... http://www.aquariaplants.com/waterchemistry.htm

 

[HeyPK]

A very short version is that GH measures the concentration of calcium and magnesium ions. KH measures alkalinity---the amount of acid necessary to get the pH down to around 4.0. I have tap water that has a KH of around 9 and a GH of 0. It has no calcium or magnesium, but the high KH is due to a lot of sodium bicarbonate, an alkaline salt. Ordinary hard water gets a high GH and KH due to calcium and magnesium bicarbonate. The bicarbonate ion contributes to the KH, and the Ca and MG contribute to the GH. Since plants need Ca and Mg, a GH higher than zero is necessary. A KH higher than zero increases the ability of the water to take up and hold CO2.