Originally Posted by beetlebz
but even though the co2 levels would most likely remain lower with surface agitation it would still provide a steady supply of co2 from the surface, more so i would think than without one. has anyone ever really accurately tested just how much co2 fish produce? im not bucking the system, just curious :)
I think there may be a misunderstand here. Surface disturbance allows CO2 to dissipate from the water, it does not bring it in to the water, ever. Oxygen enters the water, CO2 leaves; this occurs at the surface always, but adding air bubblers and surface disturbance quickens it.
The reason this is detrimental is because it takes plants some time to assimilate the CO2 and it gets removed before they can. I go into this aspect in detail in Part 3 of the series stickied, esp para 3, 4 and 5 under "Filtration," here's the direct link: