I am using pond aerator to keep the ice open and after a huge snow dump, I found the snow insulated the water and the bubbler kept a 12" hole open. In the past i used powerhead pointed at the surface to keep the hole open.
The aerator is very low power and so far so good. Was trying to keep the hydro costs down and avoid a de-icer which are 300 watts cycled on and off in -35c is likely going to cost a lot of money.
Will see how this bubbler solution works when it gets colder.