Hey Spiderweb, you make a good point there, but theres something I don't quite understand...
So when you agitate water, Oxygen levels in the water reach good saturation level, and you get gas exchange which makes the gas amounts in the water similar to atmospheric conditions, which is great for fish esp those that needs good oxygen saturaion levels.
But in a planted tank with no agitation where you're trying to maximise the saturation of carbon dioxide in the tank, respiration will reduce oxygen levels but create more CO2 in the tank, whereas nitrogen levels stay pretty much the same. So if you don't agitate the water isn't that going to be a optimum environment for plants?
And if you're injecting CO2 into the tank in the hope of increasing CO2 level underwater, won't surface agitation reduce that to normal atmospheric amounts?
Anyways, Im definately no means an expert on gas exchange, but thats how it was going through in my head. If you could shed some light on this I'd be a happy man