Thank you for such quick and quality responses.
I've spent a couple hours reading this forum and a couple weeks over the last year searching on this topic. I may misunderstanding. I thought I read bottom diffuser was best for overall health of the pond?
But George makes a point that bottom diffuser is more affordable but for a small pond top is better?
Also there might be a couple days during waterfowl season that if I have open water when everything else is frozen I might have a shot at some geese. I also heard top water aeration freezes in the heart of winter?