Hydroponics is the use of water and a nutrient solution to grow plants without soil. According to the Virginia Cooperative Extension, the nutrient solution provides the 13 elements necessary for plant growth. Along with these nutrients, a hydroponic grow system has to provide light and air. The hydroponic solution is mixed with water, providing the other basic requirement of plant growth. The hydroponic garden requires placement in an area that provides the temperature necessary for the specific plant variety. Alabama Cooperative Extension recommends between 70 and 80 degrees Fahrenheit during the day for warm season plants and 60 to 70 F during the evening. Cool season plants require a temperature 10 F lower.
Place together treated lumber to create a rectangular frame. Use treated lumber measuring 2 by 6 inches or 2 by 8 inches. A frame 4 feet, 1 inch wide, and 8 feet, 1 inch long allows you to work along both sides.
Line the rectangular frame using a plastic sheet, securing one end of the sheet using wood screws in the corners and along the sides.
Place a 4- by 8-foot piece of foam into the frame, leaving enough room so that the foam moves up and down, and so that it floats.
Fill the plastic sheet with 20 gallons of mixed nutrient solution, according to the instructions, so that the plastic is taut. Secure the other end of the plastic liner. Fill the liner with enough solution so that it is 5 inches from the top once the liner is secured.
Cut holes into the foam using a knife to fit your mesh pots into, so that they are secure and do not fall through. Fill the pots with potting medium, such as perlite, and moisten.
Add your plants to the potting medium. Check the pH of the nutrient solution regularly to ensure it is between 6 and 7. Add new nutrient solution to balance the pH when required.