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BryceM · 03-10-2006, 06:21 AM

I agree that the math according to Henry's law gives a value of 0.5 ppm for distilled water. Why then have people always cited 2-3 ppm as the equilibrium value for planted tanks? Does the presense of a carbonate buffer affect how much is able to dissolve? There is a disconnect somewhere - maybe the 2-3 ppm thing is just a myth, but it's been going around for a very long time.

03-10-2006, 06:21 AM	#31 (permalink)
BryceM Administrator Join Date: Nov 2005 Location: South Central Idaho, USA Posts: 4,262 iTrader Ratings: 42 iTrader Positive Rating: 100% Plant Points: 178534	I agree that the math according to Henry's law gives a value of 0.5 ppm for distilled water. Why then have people always cited 2-3 ppm as the equilibrium value for planted tanks? Does the presense of a carbonate buffer affect how much is able to dissolve? There is a disconnect somewhere - maybe the 2-3 ppm thing is just a myth, but it's been going around for a very long time.