Sooo Kool! my siphon has been working just fine the last 24 hours. Fish seem happy enough. I got brave enough to turn off the Tetra filter which I strongly feel was interfering with my siphon. The media bed is 3/4 filled with lava rock. I will be topping off with pea gravel. I just have to get some bacteria going.
In the mean time I will be starting my seeds in peat moss for transfer.
By the way, Drs. Rakocy and Lennard warn against peat moss for aquaponics, unless you know details of the source. Can harbor pythium fungus which affects plants. Lennard recommends coco coir, which I like too. If interested, it's available at Talini's and elsewhere, and I have some you could sample if you want.