Using ambient air you will NEVER see an over saturation of O2. The extra air will find a way to get out of the pond, even if it means sliding under the ice to the edge of the pond at the shoreline.

www.hoosierpondpros.com

[Linked Image from lh6.ggpht.com]
http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).