this is what i found
http://www.thereeftank.com/forums/sh...hlight=eductor
The tee is a 2" PVC tee. The 2" x 3/4" reducer bushings on the end of the tee have the 3/4 retainers ground flush
with a dremel tool, so that the 3/4" pipe can pass all the way through. On one side of the tee, the 3/4" pipe is
passed through and on the inside ends with a 3/4" slip x slip coupling. On the outside is a 3/4" union. On the other
side of the tee, the 3/4" is passed through the reducer bushing and ends with a 3/4" coupling. Inside this 3/4"
coupling is a 3/4" x 1/2" reducer bushing (slip x FIPT on the 1/2" side). In the female pipe threads of the 1/2" side,
screw in a 1/2" hose barb that has most of the length trimmed off. The actual "t" branch of the tee is use to suck
air. In the eductor shown, this branch is covered with a 2" x 1" slip x slip reducer bushing and a 1" street ell
pointing up. This helps eliminate splashback. The unions allow removal of the eductor from the skimmer for easy
rinsing of any salt creep that forms.