Thank you for the compliment Royce! We've been working hard to get to this point. The fish tank is a poly water storage tank with the top cut off. Since we have sand here instead of rocky soil, it was fairly simple matter to dig a hole and half bury it. We want to see if the ground temperature will help regulate the water temperature. One of the local aquapons said that he's switching from tilapia to catfish since he spent a fortune to heat the fish tank this past winter. We haven't decided what fish we will grow, but that sounds like a good idea to me.
We started to cycle our system a week ago, and already we're seeing both nitrifying bacteria showing up. My wife planted some yesterday, and soon we'll need to make the decision on the fish and get them.
I'd like to frame up the fish tank room before that though, to see if we can keep the local creatures out of the tank. Unfortunately, there's only 25 hours in a day.
Yes we did run plumbing before laying the decomposed granite floor, but there have been modifications. Our water pump is in the fish tank. It comes on with a timer and fills each grow bed one at a time using an indexing valve. To drain our five grow beds, we chose to learn from Rob Nash's experience. We're using 1 1/2" standpipes with four 1/4" holes one inch up from the bottom. These connect in the ground to a 2" trunkline, and gravity feed into the end of the raft. At the other end of the raft, we have a 2" standpipe that is 12" tall, which keep the raft water level a constant level. This gravity feeds back to the fish tank.
The plumbing all seems to work, and I was really sweating it. This is our first experience building a greenhouse and with building an aquaponics system. There are some kind and very helpful folks at a local store called Third Coast Horticulture. They've helped with design verification and supplying some of the components.
Royce, will you be bending your own hoops? You might look at Hoopbenders.net. We bought the 24' bender.
Please ask us any question you might have. I'll try to answer, out of our limited experience :)