On the Mazzei website, they show it how you describe. I thought I had tested that configuration and had no luck. I'll try it again this weekend. I'm using the Mazzei model number 287 (1/2"mnpt, 3/16 suction port).

VaughnH- I guess I can test that when I start getting mist and see inside the clear tubing if the mist is going back into the booster pump. Another person brought up the thought that maybe hobby pumps are not engineered to deal with pressure in the line. But having the injector right after the pump would probably help.

Tom-Yeah, I saw the picture that you posted. Looks great. Love the contrast of the color of the green and the wood paneling. Can't wait to see it with all the fish in. I'm sure the zoo is going to be sold on the project. I think everyones cheering for you Tom, the hard work shows.