Surface movement in the planted tank?

[LancsRick]

In the past I've always viewed surface movement as very important in order to facilitate CO2/O2 exchange to avoid suffocating fish. Now that I'm running a planted tank though, I'm keen to maximise flow within the water column to benefit the plants. Would I be right in thinking that since the tank is planted, surface movement is no longer important since the plants will deal with the CO2/O2 side of things, and that I can direct my flow to be entirely underwater, with no surface turbulence?

I've tried it just now for a few minutes and the fish seem to love it already, being much more active and playing in and out of the flow path from the pump outlet across the tank...

 

[Alastair]

personally i always ran my high tech with a light surface aggitation, just to ensure my fish were happy. i found if i had the outlet completely under with no surface movement then the fauna never seemed quite so happy, plus it helped out gas excess co2 overnight

 

[Antipofish]

personally i always ran my high tech with a light surface aggitation, just to ensure my fish were happy. i found if i had the outlet completely under with no surface movement then the fauna never seemed quite so happy, plus it helped out gas excess co2 overnight

It means you have to add a bit more CO2 than you would without the surface agitation but as Alastair says, its better for the fauna. And just because you have high CO2 does not mean you cant have high O2 as well. (Although I dont fully understand the physics of that)

 

[sWozzAres]

CO2 and O2 are independent of each other, it's the difference that matters for respiration of fauna. I have a pump pushing through a venturi style diffuser delivering air bubbles for 2 hours before CO2 comes on. It produces tiny bubbles so they stay in the water longer and minimizes surface movement. Dunno if it makes any difference though. I figure it's better for the fish and improves filter effectiveness. CO2 has to come on 5 hours before lights though.