Keeping ice from forming on ponds ??

[sunflower-n-ks]

There are lots of farm ponds around here. I have noticed a lot have things in them that roughly look like a cattle salt lick on a pole, usually toward the edge, A platform covered with a domed cover that is open at one end. I thought they were some kind of feeder, but was told they keep the water from freezing, How do they work? I assume the visible part catches the wind to operate paddles or something that is under water?

[Bearfootfarm]

It could be an aerator.
Pumping air to the bottom of the pond will bring warmer water to the surface

[Darren]

Air bubbles released below the surface will keep ice from forming. I don't know where you are located. Might not work in Alaska. other places it's used in marinas to prevent ice formation.

I've used an aquarium bubbler in a small pond to do the same thing.

[sunflower-n-ks]

I am in Kansas, so we get some days around or below zero. More this year. But not the extreme like in some parts of the country.

[ronbre]

probably an aerator...they work fairly well here in Michigan but some ponds will still freeze with them..sometimes just a ball or log will help keep a free of ice spot