[Samw]

Come on Bob. No one is arguing that oxygenation doesn't occur at the surface. That's what the skimmer does. If you are going to say that the skimmer doesn't add oxygen to your tank, at least have a way to back it up by having some measurements before and after. If you can measure your tank before a skimmer is added and after a skimmer is added and show that it doesn't raise a tank's DO from a low level to a high level, then you'll have a point.

If you think that I am saying oxygenation does not occur at the surface, then you are arguing for the sake of arguing since that is not what anyone (myself nor Eric) is saying at all.

You can have an Angel in a small tank without a skimmer of course. There is more than 1 way to oxygenate a tank. Just because you can keep a whole angel in a small tank without a skimmer doesn't mean that skimmers don't oxygenate tanks.