Water straight from tap - pH7
Tap water after 24 hours - pH7.4 (the water company adds CO2)
Tank water after CO2 injection - pH6.5
Tank water after 24 hours - pH6.9
My KH is 4 so I should have CO2 at around 34ppm. But my tank water has a lower pH than from the tap, I'm assuming because I have two largish pieces of driftwood. So how do I measure CO2, taking into account the fact that the wood is lowering my pH?
Tap water after 24 hours - pH7.4 (the water company adds CO2)
Tank water after CO2 injection - pH6.5
Tank water after 24 hours - pH6.9
My KH is 4 so I should have CO2 at around 34ppm. But my tank water has a lower pH than from the tap, I'm assuming because I have two largish pieces of driftwood. So how do I measure CO2, taking into account the fact that the wood is lowering my pH?