There is no need to increase KH
as a result of Co2
input. The injected co2
will drop the pH but will not change the KH
. However, if you were to change the pH in a tank, you alter the form of inorganic carbon. The lower the pH the inorganic carbon will be mostly co2
and as the pH increases the carbon becomes mostly bicarbonate then carbonate.
I donít think the water is cloudy because of the co2
. Have you done any large water changes, gravel vacuuming or filter cleaning recently?
How new is the tank?
I do agree that you need more plants to make use of the co2
. Mainly because you will have more oxygen which is probably more important than anything as far as aquariums are concerned.