You can either move one or two into an area that is approx. 1/4 the total pond depth for the winter and move it back out for the summer, or have a manifold box on shore and just turn on and off different ball valves.

Buy the back issue of the Pond Boss Magazine that was Jan/Feb this year (2015). Bill Cody and I did a winter aeration article.

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).