I finally got the third system up and running, I was waiting for the
seeds to sprout and get big enough. This is a simple flood and drain design using 4 inch ADS tubing, similar to P.V.C. but it's designed for irrigation. You should be able to find it in the same isle as the P.V.C. tubing at Home Depot and Lowe's hardware stores. The ADS tubing looks much the same but is made of 3 different layers. The inside layer is black (and lightproof), the second provides structural support, the last is the white outer layer. This stuff is real easy to cut and is inexpensive at about $8 for a 10 foot tube. The end caps were $1.97.
I cut holes in the end caps to insert the through holes, then flooded the system to mark where I was going to glue the end caps in place. I just used regular P.V.C. glue that I already had. I also already had the threaded elbow connectors for the P.V.C., and the pieces of 1/2 in P.V.C tubing used for the overflow tube. You will notice on the overflow tube there is a "T" connector with a piece of tubing extending up, then some holes drilled in the end cap of that tube. This is to insure there are no air bubbles that can get trapped in the overflow that might cause it to not function properly. Also the long black piece of P.V.C. that runs the span of the tube is just one I already had from long ago. It had been in the garage so long that it was bent so I just zip tied it to a long piece of wood to kind of striation it out.
The
nutrient reservoir is one that I am reusing from my pepper plants last summer. I painted the top black (to lightproof it) then white (to reflect light). The bottom part is actually two containers, one inside the other with spray insulation foam between them. So the insulation provides the light proofing. The stands were just made from 2x4's then painted white. I used a 4 inch tube coupler that I cut in half, then screwed them to the stands for the tube to rest in. I used a buggy cord over the top of the tube (to hold it in place).
I have 3 diffrent plants in this system peas, sugar peas and green beans. I will be building a trellis (similar to the one I have for my tomato's in the background) for these to climb on. I will also be adding summer squash to this system. Though the squash will actually be a
drip system running from the same
pump. So I will have both drip, and a flood and drain systems running from the same pump. I have a one way flow valve that I got for $8 that will be inline with the drip system. This will allow the nutrient to flow to the drip system but when the pump shuts off it will close. This wont allow any back flow from the drip side of the system that would allow air bubbles, and then stop the siphoning back to the reservoir from the flood and drain side of the system.
ADS tube $8
end caps $1.97 x 2, $4
pump $44
through holes $1.97 x 2, $4
tube coupler $2