Enough Gas Exchange?

[Myka]

The fish don't care about micro bubbles, but many corals will be irritated by them.

[Ryan]

Thats why you would put them in the 1st chamber of your sump so the baffles take them out.

Nowhere did I say to put them in a display tank but no "rolling" the surface will not help build O2 levels it will just help the water move around. You have to break the surface to help with 02.

Your skimmer, dual overflows, the water entering the sump as well as the water going over your baffles all helps in oxygenating the water.

[naesco]

By placing a power head near the surface of the water in your display tank you are accomplishing 2 things.
1. You are mixing 'more oxygenated water with less oxygenated water which is found lower in the tank.
2. If your power head is creating a ripple effect on the water surface, the water is being oxygenated in the same way that a moving steam in nature is as opposed to a sitting pond for example.

No scientist here but it makes common sense, doesn't it?