Another option is to let all the air travel to the shallow diffuser which will make a larger open water hole in the ice. IMO larger open water is better than smaller in ice and snow cover.

Here is link to another discussion about potential winter kill under the ice and snow:
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Main=28519&Number=365263#Post365263

Last edited by Bill Cody; 02/15/14 10:40 PM.
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