Pictures as promised. I used about a foot of radiator hose off the pump because it all does get hot. The diffuser is at about 7.5 to 8 feet. The pond depth is 8.5 to 9 feet. I tried to find the absolute deepest point but failed, hope it doesn't make that much difference. The Gast registered 0 PSI with just the tubing connected. Deployed at 7.5 feet the pump registered about 5.5 PSI. I opened one of the valves in the manifold box (constructed of old plastic decking boards) so that the Gast is running at 4.5 PSI. Doubt I'll ever use that third valve, but I may put a shallow water stone diffuser on that second valve that is just wasting air. I'd say the column of air is about 2.5 feet wide. The diameter of the boil with white water is about 5-6 feet. The area of rapidly moving water is about 8 feet in diameter. Comments?

http://berryfieldfarm.com/Gast.jpg
http://berryfieldfarm.com/Box.jpg
http://berryfieldfarm.com/Box2.jpg
http://berryfieldfarm.com/Boil.jpg

I'm more like a pond servant.