Is It True That The Tank Doesn't Need Bubbles?

[andywg]

And to add to that, if your setup includes live plants you not only don't need but don't want bubbles.

Why is that?

You don't want any surface agitation in a planted tank as it will drive off CO2.

Using a CO2 line into an air stone shows how little diffusion takes place across bubbles in the water. If you have a tank that has been supplied with an increased level of CO2 and then connect a second CO2 device to an air stone, the level of CO2 will drop due to surface agitation gassing off the CO2.