disconnect co2 at night?

[serbusfish]

Correct. The CO2 will continue to be added to the tank, but the airstone will create enough surface agitation to gas off the CO2 so that it doesn't suffocate the fish overnight. You also won't lose any pressure that way, so when the air-pump turns off the CO2 will go back to dissolving in the tank.

OK great, cheers, now I need to try and find an air pump that is REALLY quiet (my tank is in my bedroom).

Unless you have some strong lighting, CO2 isn't even needed.

What?? I have been told all plants will benefit from having co2, in fact the guy at the store told me to put the co2 in, take a picture, then a week later take another picture to compare because the difference would be that big. He the Dwarf Sagiteria I have will grow much thicker due to co2 being added.

Was it all sales crap? This guy is well known to us and someone I thought was very trustworthy for info.

BTW something im wondering about using this method for co2 is the PH, I will have to refill the container ever 40 or so days, and as it takes 24 - 48 hours for the co2 to build up surely my PH will be all over the place?