New system in greenhouse

This is the new system I started in the greenhouse. I hope to have it cycling by the fall planting season. I hope to move the other two grow beds in here soon.

I got away from the small river rock and invested in the expanded clay. I did use river rock on the bottom to stabilize the automatic siphon system. 

Very happy with the way it turned out. 

I was concerned that the fish tank would get to low if it worked out that both grow beds filled at the same time, however that was not the case. Plenty of water in the fish tank, guessing at least 2/3 full. I put one tilapia in the tank 12 hours ago and she seems to be doing fine. After 24 hours I will put 3 more in.