Here are some additional threads and information that might be helpful.
Pressure calculation thread Aeration simplified thread Water head pressure table Note on the table, it is .43 psi for each foot of depth. As esshup pointed out in one of the other threads linked above (and Bill Cody mentions in his post), .5 psi per foot is a good rule of thumb figure to use as it allows for a small additional back pressure from friction in the supply line and diffuser.
You are getting me excited about getting my system back in the water in a more permanent fashion than it was last fall. Getting that time of year.
