I see a 0.3 acre blue pond and a 0.9-acre pond in the field. I assume the field pond has no electricity, but the small one looks like it might have a dock and possibly some electricity.
The small pond might squeeze by with a Small Pond Aerator. They sell for $375, but the pond can't be more than 8 feet deep. If it is, the diffuser will have to be blocked up to keep it from being any deeper than eight feet.
The pond in the field needs electricity, but could get by with a single diaphragm windmill. I would lean more toward a dual diaphragm. In either case, they would be better off with a Vertex Co-Active AirStation for maximum performance.
AquaTron would be a good choice for microbes also.
EMAIL ANY TIME DAY OR NIGHT