I have been asked to add some technical information about my garden system. My system is really simple and anyone could build one. The only problem will be the bags of pine bark that I use. I don't know of anyone but Phillip Brothers Bark Processing in Brookhaven Ms. The bark in these bags has been composted for about 9 months. It smells more like soil than it does pine bark. Its about the consistency of  coarse potting soil. The bags weigh  50-60lb.

I really don't see why potting soil would not work if you could put it in bags and punch a line of holes along the bottom of the bag where there will be about an inch of nutrient in the bottom of the bag. I use the holes to judge how much to feed the plants. A good rule of thumb is to have about 5% of the nutrients to run out. This keeps salts from building up in the bottom of the bag. It takes a couple of years use to build up a lot of salts in the bags but by the third year you will be replacing the bags anyway because the sun will have them falling apart. I am going to take the old bags and empty them in a raised bed and keep using the bark. What I try to do is just keep the bags running over. At the output of my pumps I have a 3/4 in. "Y" connector that you use to connect two garden hoses to one faucet, It has shut off valves on each connection. I use one connection going to the plants and the other is bypassed back to my tank. With this arrangement I can regulate the pressure and also keep the system from siphoning.

I watch the overflow and keep increasing the pressure just enough to keep a little running out. You will be amazed when the tomatoes are putting on fruit, how often you will adjust the pressure. They can really soak it up.

I use 1/2in.  pvc down each row with a 3/64th. hole at each plant.The size hole is very important. I spent a day trying to figure out what size to use. You would think that if you started off with a small hole and got a little larger down the row you could make the amount of nutrients by each plant about the same. THIS IS NOT SO. The 3/64in. hole is almost perfect. You get about the same rate from one end to the other. I feed 12 times a day for one minute (about 10oz.) from transplant to first fruit then increase the time to two minutes during the hottest time of the day. When the temp. reaches 95+ I feed two minutes every feeding.