I saw a 2 bucket hydro garden powered by an air
pump at a grow store but it had a tree growing in it so I couldn't look inside. So I went home and what is called reverse manufacturing I tried a few designs and came up with what worked for me. Try it, you will be surprised how well it works.
Ask a physics teacher how it works. I don't know. I slept through that part of the class. I use what is known in the unscientific community as trial and error. I keep trying until I get all the errors out and the garden works.