:gpo2:
As far as I know, plants start to use CO2 as soon as the lights come on whereas CO2 takes a while to fill the water. By the time the lights come on, the CO2 has a one hour head start and giving the tank one hour for the plants to use the last of any remaining CO2 ensures the fish are kept happy and healthy :thup:
I just noticed your location, feel free to PM me if you wanna take a look at my tanks or visa versa, I'll be just down the road no doubt