I can't help Uncle Sean with his criteria but my Windmill worked great for 10 years.....it still does but I need to renew the pump which quit last year. i have the stuff to do it with; purchased when new. My pond windmill is wide open from all sides and there is not many times it's no spinning.

I do want to look up solar aerators people have because when I look up what is for sale; they are much more expensive than a windmill aerator.