The back-up wood heater is in the building. Now I can get busy setting tank supports. I have one of the IBC's cut, and I have my first problem. If I set it up the way the book and video's say to, I can't use the main drain valve. I am putting a submersible pump in each tank, but also need to draw off the bottom valves for the rest of the system.  As it stands right now there will be 4 IBC fish tanks w/grow beds. Then there will be 10 grow beds made from 55 gal blue barrels cut in half longways, and finally there will be about 60 ft of pipes  to grow in.The biggest challenge I see is keeping the water all going down hill :) I have a short wife so my elevations are limited. I may end up adding a sump tank and another pump.