from the sounds of it u have a diffuser in your tank..... if it is set up properly then nearly all if not all the bubbles should be absorbed into the water before they reach the surface.. if not you are wasting the co2 (would be the same as having a rough water surface).
you shouldnt need a powerhead as your filter will already be creating a water movement/current
I used a Hagen ladder for a while in my 33 gal. I barely keep a good CO2 dissolution. Now I have a dedicated power head (Maxi jet 900) I run the CO2 by the intake with a 3/4 inche bamboo chinese stick that create micro bubble. The exit side is a plastic clear tube from a old undergravel filter transform in a reactor to maximise bubble travel. the result dissolution and distribution is 100% better.