Hey all thanks for the help. I think I screwed up the pump with hydroton dust... Home depot was happy to take it back -I didnt tell them it was making noises. I got a stronger pump. I think the problem is that my siphon's middle part? (the part that sticks up in the middle, inside of the siphon, not the strainer) is 1/2", and it goes into a 1" pvc down into my rez. Sometimes it kicks on, sometimes not. When it doesn't it just trickles down as if the siphon wasn't there.
I also played with turning up the pump, and noticed that it kicked on better when I was filling the beds faster. Once it kicked on, sometimes, after draining, it would break the siphon, other times not. When the pump was going faster, it seemed like the siphon wasn't draining fast enough to compensate for the water coming in. The siphon just wouldn't break.

I'm assuming the real issue is the 1/2" to 1"... would 3/4" to 1" work? Or does it have to be all the same 1" or go from bigger (1") to smaller (1/2") (as opposed to small (1/2")to big (1") in the siphon loop -which is what I have now)? Thanks for the help guys, I'd like some clarification on that pvc sizing before going back to the "depot"
If that is the problem, I dont get why it would work sometimes, and not others. Shouldnt it just never work or always work, since Im not really changing anything?
Also the beds dont drain completely, but mostly. I assume that's how it works, draining to where the siphon break gets to. But I thought I'd ask anyway.