Initially I planned on constructing the greenhouse by myself. However, after conferring with my parents, my dad offered to call his carpenter friend. This turned out to be an excellent idea considering I have no idea how to construct anything really. So a step that would have taken me a good couple of weeks took all of two days as the carpenter was very professional.
Greenhouse site before:
Finished frame (9/17/10):
Since then I haven't made as much progress as I would have liked but it's been coming along. Figuring out the best way to support the grow beds and figuring out exactly how to plumb it took some troubleshooting but I think we have it figured out for the most part.
Here is how I pictured it initially:
The green squares represent the growbeds, the darker blue tanks are the fish tanks while the lighter blue cubes in the ground represent the sump tanks.
Because we are primarily using gravity to direct the water, it was necessary to raise the first level of growbeds on the right (So that we could drain the water to the 2nd level of grow beds that sit a few feet below the first level. The 2nd, lower level of grow beds is not pictured) I didn't want to use wood as I wasn't sure I could build something strong enough and because it would eventually rot. Pavers were a possibility but didn't want to spend too much money and because the greenhouse floor is not exactly level, I was afraid of stability issues. Finally my dad came up with an idea to use the bottom half of the IBC metal turned upside down to support the top half.
However, when we filled it with water during a siphon test, we found that the two metal bars that ran across the top of the IBC were not quite strong enough to support all of that weight (once full of water and gravel I expect each grow bed to weigh about 1.5 tons). This probably should have been expected because I'm taking the top half of these containers and using it upside down. Once again my dad came to the rescue. He told me he had these metal beams at his warehouse that is used to shelve pallets of tiles that weigh 1 metric ton+ (Thanks again dad!)
I haven't filled it yet, but those things are damned sturdy, I'm sure they will do the trick. I'm probably going to run the original bars perpendicular to the pallet beams to add a little more support but I don't think we will have to worry about it too much with these massive things.
So I think the grow bed support issue is finally solved (Doh hope I'm not speaking too soon).
Next up: Plumbing....