Instead of feeding grain to my farm animals (pigs, goats, dairy cow, chickens), I wanted to feed them nutrient-dense grass/fodder. So I built this system. Some of it is dependent on the resources I had at hand (a generally unused shower, for example), but the principles can be carried across various adaptations.
-1" PVC pipe
-1" PVC T-joints
-Plastic drip-edge (you can find these at Lowe's or wherever)
-Silicone caulk (important: don't use latex caulk! It's not waterproof! Use SILICONE only)
-24" plug-in fluorescent light ballast & two bulbs (a natural daylight one, and a soft white one, to provide various spectra of light)
-An old shower or otherwise waterproof place to build it
-A space heater, radiator, or other way to keep the room between 65-70 degrees F
I'll explain the process, but it may be better just to check out my video to see how the final product looks.
-Cut 24" side rails for the structure from the 1" PVC. -- You'll need 8 of these
-Cut ~18" legs for the structure from the 1" PVC -- You'll need 16 of these
-Cut slit down the middle of each rail with a circular saw, leaving an uncut portion on about 1" of either side of the rail
-Cut ~22" back rail for each growing platform (4)
-Cut slit all the way down each back rail
-Measure and cut tileboard to fit inside the side rail slits and to match the width (plus 2" or so) of the back rail
-Push the tileboard into the slits of the side rails and the back rail
-Cut the plastic drip edge to fit on the one exposed side of each platform and push it onto the platform
-Glue, with adhesive, aluminum foil onto the bottom of each platform. This serves two purposes: sealing the porous bottom side of the tileboard so water can't get in, and reflecting ambient light down onto the growing fodder below. Make sure you seal all the edges of the underside as they contact the PVC and the foil.
-Let the adhesive totally dry.
-Fit together the legs into the T-joints, and then push the platforms into them to create the structure.
-Use silicone caulk to caulk every joint on the top of the platforms and the joints where the back rail meets the side rails. The point here is to ensure you don't let ANY water get into a porous area of the tileboard. Make sure you caulk the drip-edge seam where it touches the tileboard surface.
-Prop up the back side of the structure so water will naturally run off the drip-edge side.