Hi everyone,
This is an extract of the article on CO2 by ceg4048,
"The relationship in practical terms therefore is that if Hobbyist "A" has tap water measuring ph 7.2 and kH 10 ( high levels of carbonate and bicarbonates) then 30 ppm of dissolved CO2 may only cause his pH to drop to 7.0
Conversely, Hobbyist "B" has tap water also measuring 7.2 but kH 6. More acid can form in his water (because of less carbonate and bicarbonate levels), so 30 ppm dissolved CO2 in his water will result in a pH drop to 6.8."
Ok Id like to understand this better because Im a bit confused. I thought that to get 30 ppms (or any ppm of CO2) the change in pH would have to be the same (e.g 1(aprox) for 30 ppm) no matter what KH the water is. This is what I understood from Tom Barr.
So to understand this better:
Hobbiest A, water of KH 10, His pH would drop 1 unit.
Hobbiest B, water of KH 6, His pH would drop 1 unit as well.
To get another ppm of CO2 the water would change X units of pH, but it should be the same X amount for a different water with another kh.
We can check this with the pH-KH table. You can try doing it with two different kh waters. The result is that the change in pH is the same for both if we have same co2 ppm. I know ph kh tables dont work very well for real waters but for this comparison its appropriate, I would've thought..
What am I missing?
Thanks all!!
This is an extract of the article on CO2 by ceg4048,
"The relationship in practical terms therefore is that if Hobbyist "A" has tap water measuring ph 7.2 and kH 10 ( high levels of carbonate and bicarbonates) then 30 ppm of dissolved CO2 may only cause his pH to drop to 7.0
Conversely, Hobbyist "B" has tap water also measuring 7.2 but kH 6. More acid can form in his water (because of less carbonate and bicarbonate levels), so 30 ppm dissolved CO2 in his water will result in a pH drop to 6.8."
Ok Id like to understand this better because Im a bit confused. I thought that to get 30 ppms (or any ppm of CO2) the change in pH would have to be the same (e.g 1(aprox) for 30 ppm) no matter what KH the water is. This is what I understood from Tom Barr.
So to understand this better:
Hobbiest A, water of KH 10, His pH would drop 1 unit.
Hobbiest B, water of KH 6, His pH would drop 1 unit as well.
To get another ppm of CO2 the water would change X units of pH, but it should be the same X amount for a different water with another kh.
We can check this with the pH-KH table. You can try doing it with two different kh waters. The result is that the change in pH is the same for both if we have same co2 ppm. I know ph kh tables dont work very well for real waters but for this comparison its appropriate, I would've thought..
What am I missing?
Thanks all!!
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