This is over my head.the only thing I did know about airlift systems was from reading and watching utube. I have a few months of experimenting now and I can share this, with a 60 watt air pump and 3" pipe, 5-6' seems to be the best depth. I have tried air stones and manifolds, but I get more flow with air piped straight in at the bottom of the pipe. You can put an elbow at the bottom and draw water from any depth, even an inch below the surface, as long as the main vertical pipe stays at 5-6,.
