- Joined
- Apr 22, 2018
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- 460
I agree that alk and calcium are not affected by ambient co2. However alk and calcium USAGE are effected by ambient co2. In other words, your tank will use these elements faster when you open the windows.Alk and calcium levels are not affected by ambient CO2 levels. pH is. Your anecdotal observation implies that perhaps the Hanna alk checker is sensitive to pH changes. I own a Hanna checker, but rarely use it. I wonder if others have reported a similar pH-sensitivity?