[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: ph-kh-co2


The formula you and George settled into:

	CO2(ppm or mg/l) = 12.839 * KH (dH) * 10^(6.37-pH)

Sounds just like the previous "rule of thumb" formula:

	CO2(ppm or mg/l) = 3.0 * KH (dH) * 10^(7.0-pH)

Since you can just multiply the constant by 10^(-0.63), giving you 3.0098
and carry the inverse 10^(0.63) into the pH term, giving you a 7.00 reference.

The latter is simpler to use, but former gives you a clue as to where the
"rule of thumb" comes from (which I wasn't clear on before, thanks Roger and

Carlos Munoz