This is what I use. It's 23 feet tall, cost around $1800. Pricey maybe but it looks good and uses no electric power. Might take a long time to recover that cost in power savings, but I've always wanted a windmill and I finally had an excuse to get one. The air line runs underground down to the building where I have an adjustable splitter and from there out to the two ponds. The air stones are about 7 feet deep in each pond, and it pumps a decent amount of air into each pond. The website where I ordered it from is pondaeration.com.
