Planted Tank Guru
Join Date: Jul 2010
Location: Denver, CO & Phang-Nga, Thailand
What about having decent surface agitation from the filter/powerheads, running CO2 during the day, and running a bubbler during the the night? The plants need very little CO2 during the night when the lights are off, and the bubbler ensures that CO2 doesn't accumulate and that oxygen levels are also good?
I do this in my tank, actually. During the night, I've noticed that the bubblers make the currents change slightly in the tank, which makes the plants wave around in a slightly different way and the debris on the bottom is kicked up each night. That seems to have a long term effect of making the tank cleaner and the plants sturdier.