I'm using a 1/3 hp rotary vane compressor that runs to two airlines and two membrane diffusers, which I'm pretty sure are 9 inch. (1/2 inch air line) Water depth of each diffuser is in 8 to 9 feet of water. Pond is .62 acres.

There seems to be pleny of air for each diffuser and i haven't changed the vanes for three years!

If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.