Got up & running for the plumbing check/tuning yesterday.
Very interesting part of the system. I was thinking I wanted at 5" deep grow bed, for mostly, Lettuce, Kale, Swiss Chard and Parsley, Cilantro, Basile, So I thought I'd have the stand pipe @ 4" + 1" extra media.
After a lot of Trial/Error I really found it interesting the relationship of the Return Drain pipe length to the Stand pipe height in how fast the full suction works.
Also after getting a bit carried away micro-managing my Bell Syphon height I de-railed the process around 11:30 last night.
I went on Youtube and found a Video that talked about 1/2 to 1" inside space between the stand pipe and the Bell Syphon Cap head. So, today I'll cut some more PVC and hopefull get it right.
I also feel maybe with my rack & length of drain pipe, a bit taller Standpipe will work better. I'll start at 5" today. That will of course require the media bed to be deeper. Which is only a $$$ issue as I can imagine the Veggies will care.