Well this is actually a continuation of another thread, but I thought I would start a new one sense it is a new start for my tomato's. It is basically the same setup with a couple of modifications. The geothermal reservoir is the biggest one. It is going to get too warm to keep the
nutrient s outside soon, so I built the geothermal reservoir to keep them cool. Basically it consists of a 32 gallon trash can that's permanently in the ground. With a removable 20 gallon trash can inside of it, and buffer between them. The buffer water is to allow better transfer of heat from the nutrient solution (in the 20 gallon trash can) and the ground, but still allow the nutrient reservoir to be easily removable for maintenance.
First I had to dig the hole, that was a real feat. It took me 4 days, and I still wanted it 6 inches deeper. But I ran into 2 rocks I just couldn't get out, so I settled for 30 inches instead of 36 inches deep. Once I had it dug I sifted the unearthed soil to get the rocks out to back fill it with. That way it wouldn't damage the reservoir as it settled back down. The pile of dirt next to the wall behind the hole is the sifted soil. The dirt in the 5 gallon bucket is the sifted soil before I put it on the pile. The green bucket next to it is the rocks that I got out of just that one 5 gallon bucket of sifted soil. The hand scoop I already had from metal detecting. I was going to get a spaghetti strainer from the dollar store before I remembered I had it.
I had to cut the handles off the 20 gallon reservoir so that it would fit nicely inside the larger one. Then I cut two circles of 2 inch thick Styrofoam, one for each trash can. this keeps the heat out from above ground. Then I made a handle for each Styrofoam insert to easily take them out. To make all the holes line up for the over flow tube, I simply places the 2 Styrofoam inserts in place, then the trash can lid. I took a thin metal rod, heated one end and then stuck it straight down through all 3. That way I knew that they would all line up. Then I just made each just large enough for the tube to go through.
The blue things around the over flow tube is just a home made washer, made out of a small piece of thin insulating foam that I already had, and a rubber band to hold it in place. That way I can set it in place, then put the trash can lid on top without needing 3 hands. The blue insulation foam around the 2 gallon buckets I already had (the same I used on the over flow tube). The pipe insulation on the P.V.C. tubing, I also already had. I will also be putting pipe insulation on the black 1/2 inch vinyl tubing from the
pump to the P.V.C. in the future. That's basically the new setup.
P.S. I will still be finishing the reservoir off by placing something like bender board (for garden edges, only 12 inches wide) in the ground around the trash can. Three to four inches deep, and about 8 inches above ground. Then I will place a mound of dirt all around the outside of it. That will be a 8 inch high mound of dirt all around the reservoir. This will keep rain water from overflowing into the reservoir and flooding it. I will also be placing a flat board over the top of it, this will help keep it cool, and the warm air and rain out. As well as adding a few inches of depth to the system.
The large trash can was $10
The small trash can was $12
The Styrofoam sheet was $6
Digging the hole, Priceless