1 -1/2" barb
1 - 1/2" ball valve
and 2" of 1/2" hose.
Put them together, and put the hose over the air inlet barb. This lets you adjust the air input, and you get much smaller bubbles. Seriously improved my RD III.
I don't think the RD is designed for the flow you would need to properly run a beckett.
[ September 02, 2001: Message edited by: Redneck Cowboy ]