Growing vegetables hydroponically has several advantages over traditional gardening techniques including: healthier plants, better use of natural resources, less pollution and high yields of fresh vegetables in small spaces. According to Sparks Lab, "Hydroponics... uses as little as 1/20 the amount (of water) as a regular farm to produce the same amount of food." Growing vegetable crops hydroponically requires controlling the factors that impact successful plant growth such as nutrition, light and temperature. A relatively simple hydroponic system for growing vegetables uses gutters or pipes and a nutrient film technique (NFT) to provide nutrition to the plants.
Select two stands to support the hydroponic growing container at either end making sure that one stand is slightly higher than the other so that there is a gentle slope between them. A slope of 1:30 or 1:40 is recommended.
Purchase a PCV pipe that is three to four inches in diameter and cut to the length necessary to rest on top of the stands. Seal each end of the pipe with an up-facing elbow PCV joint or PCV cap. Drill holes in the top of the pipe to hold vegetable plant containers. Drill two small holes at either end of the bottom of the pipe for the nutrient feeder tube and the drain tube.
Place a tub beneath the two stands to hold the nutrient solution. Place a pump into the tub and connect a tube from the pump to the higher side of the PCV pipe through the small hole in the bottom of the pipe. At the lower end of the pipe, place one end of a drain tube and place the other end of the drain tube into the tub. This setup allows nutrient solution to be pushed into the pipe from the tub, flow slowly through the pipe and then drain back into the tub to be recycled.
Select vegetable plants and place them into containers with a bottom hole large enough for the roots to dangle into the nutrient solution. Fill the containers with inert material, called growing medium, such as vermiculite, perlite, coconut fiber or rock wool to support the vegetable plants in an upright posture.
Place the containers with the vegetable plants into the holes in the top of the PCV pipe.
Fill the tub with commercial nutrient solution and turn on the pump.
Place a grow light above the vegetable plants if growing indoors. The plants need 12 hours of light per day.
Maintain a temperature of no lower than 45 degrees at night and approximately 70 degrees during the day for cool season vegetables such as salad greens.
Check the fill level on the nutrient solution weekly and monitor the pH of the solution using testing strips. Keep the pH between 5.5 and 6.5 for your vegetable plants.