A Kasco surface aerator would work well or like the article said you could use a de-icer mounted on a frame.

https://kascomarine.com/products/pond-lake-aerators/
https://kascomarine.com/de-icers/

This is what I am going to set up in the next few weeks, I will set it in 4ft of water with the diffusers 30" off the bottom. I am going to try out an Ecoplus 7 aerator to see what kind of boil I get off of it.










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