Thanks for the interest CrossOps,
Yes, we got the second Sub "T" system in the ground last weekend, along with the other two
nutrient reservoirs. Right now I'm in the process of leveling the backyard out again, as well as creating the boarders for the nutrient reservoirs (like in the 3D drawings). The lady looking down into the hole is my mom, she's checking out the mess I made (her recent favorite saying these days). I still didn't get all the 4 inch corrugated tubing in the second system I wanted, but I did get about 4 more tubes in it than the first one. I could have gotten one more in, but to do so I would have needed to cut it from a new 100 foot roll. Therefore I couldn't return it, costing me $55 to get just one more 12 foot long tube in the ground. So I decided it wasn't worth the money to do so. In total I have almost 400 feet of 4 inch tubing in the ground, witch isn't the 600 I was hoping for (doubling the recommended amount), but still almost 100 feet more than what's recommended for a greenhouse this size. As well as still capable of circulating 310 cfm at the recommended not more than 10 cfm per in-ground tube. So I'm still able to be well above the recommended circulation of the entire air volume of the greenhouse 5 times every hour (once every 12 minutes).
3000 cubic feet of air to circulate, 31 tubes in the ground.. At 10 cfm each that's 310 cfm the two systems can move underground and still work correctly. 3000 divided by 12 equals 250 cfm (that's the needed cfm to circulate 3000 cubic feet of air 5 times per hour). But actually I purposely inflated the cubic feet of air needed to be circulated to 3000. In actuality it will be more in the neighborhood of 2300 cubic feet of air in the greenhouse. Needing to move 191 cfm to circulate the entire air volume of the greenhouse 5 times per hour. Moving 310 cfm through the system will basically circulate the entire air volume of the greenhouse through the system (underground) about every 7-1/2 minutes (7.419). So even though I don't have two complete sub "T" systems in the ground/greenhouse, what I have been able to get in place should still be well more than sufficient.
If you look closely an the picture inside the barrel, you'll see there is some insulation (blue board Styrofoam insulation) at the separation between the bottom warm air inlet, and the upper cool air outlet that wasn't in the first system. Well it was supposed to be in that system before installation too. But I simply didn't have time for the silicone (and spray foam insulation) to cure before we installed the barrel. So I will be adding it later after I level the ground out, and while it's in the ground.
You'll also notice the top of the reservoirs are covered, that's to keep dust and dirt from getting into the reservoir (but it still gets in there). In pictures of the first Sub "T" system and first reservoir you can see that I cut the top of the water storage tanks, then used the part I cut out to make a lid. I will show more about how I did that, and the materials I used to create the lip when I take a few more pictures. I also have a couple more alterations I need to do to the lids first as well, and I will show how I made the borders around the reservoirs at that time as well.
P.S.
The shirtless guy in the hole helping me back fill it is my buddy. He will be 65 in a couple of months, but he can out work anybody I know. Even at his age he can out work guys 30 years younger. I would be willing to bet you don't know anybody that has hand mixed well over 50-60 bags of cement (one or two bags at a time) in a wheelbarrow to build a retaining wall in his backyard (all in one day). Simply because it would have cost about $120 to rent a cement mixer to do it, and didn't feel like spending money to do something he can do without spending it. That was less than two years ago. I got burned out mixing just 2 bags of cement to install the post for our mailbox about a year ago. Can you guess who I plan to hire to help me mix the cement for the 8 posts needed for my moms fence I get to build after the greenhouse is done?