the floating de-icer looks exactly like the one stoney creek has on their web site.

A farmer I used to work for, had used 2 of them to keep his watering "pond" open for the cattle, he claimed at the time, that it did not run all the time(thermostat) and didn't cost to much to run, I don't know, I was curious if anyone here used them for their pond. I beleive, but could be wrong, that one can be purchased locally for around $30.

I didn't want to move my "deep" diffuser for fear of damaging the supply line, so I thought I could just disconnect it at the compressor and run a short line with a stone type diffuser or what ever is suggested to the shallow water, wich I could remove and store during the summer.