Okay... I got the demo system on a trial run.   One problem I am having is that I have some leaks... I've tried twice to fix the with aquarium cement, but still an issue, as there's an area of my grow bed that cracked.   It's a fairly small leak though, and I think I can work with it.   The bigger problem is that I can't get my bell to siphon.   Not sure what I did wrong.    Gotta fiddle around with it some more.    Our 4H gardening clinic is less than a month away now, and I'm getting a…