The pH/KH chart is often used to get a reading of CO2 levels in the tank. However, many folks go about this the wrong way. If you are estimating CO2 levels using only 1 pH reading - then chances are you are getting an incorrect estimation of CO2 levels. Read on to find out how to read pH/KH chart correctly.
Gasping fish does not always mean you necessarily have good CO2 levels. This page explores the paradox of tanks with poor gaseous exchange, that suffer from both gasping fish and poor CO2 levels at the same time.