Assemble your basic hydroponic system which consists of a tray or reservoir for the nutrient solution, a pump, nutrient tubes, pump timer, plant tray and a drain tube.
Attach the nutrient distribution system to one end of the nutrient tube; attach the other end of the tube to the pump. The most popular hydroponic system for vegetable plants is a drip system which uses a manifold mounted above the plant tray to drip nutrient solution onto the plants.
Attach the drain tube from the plant tray to the nutrient reservoir to return excess nutrient solution.
Purchase plants for transplanting or use seedlings grown indoors that are at least 3 inches tall.
Purchase growing medium such as rock wool, perlite, coconut fibers or vermiculite and containers for growing your vegetables. The containers should be large enough for the roots of mature plants so the right size will depend on whether you are growing lettuce or tomato-sized plants. The containers need to have several holes on the bottom to allow the nutrient solution to reach the plant roots. Special purpose containers, called net pots, are available from hydroponic specialty stores.
Gently clean the vegetable transplant's roots by shaking away the soil. Be careful not to touch or damage the delicate roots. Place the plant into a container and set the container onto the plant tray. Fill the container with growing medium.
Fill the reservoir with commercial nutrient solution. Set the timer to distribute the nutrient solution to the drip manifold every 30 minutes to 1 hour depending on the vegetables being grown.
Suspend a grow light above the plant tray. Cycle the light with a timer to ensure that the plants receive 14 to 16 hours of light per day.
Replace the nutrient solution as needed, but at least every week. Check the pH of the solution using pH testing strips. Keep the pH between 5.5 and 6.5.
Maintain the ambient temperature at an appropriate level for the vegetables you're growing using a thermometer. Cool season vegetables, such as lettuce, prefer temperatures below 75 degrees with cooler night-time (dark) temperatures, whereas warm weather vegetables, including tomatoes and peppers, like temperatures that range from 65 degrees to 85 degrees.
Check your vegetable plants every other day for any signs of distress including yellowing or wilting leaves or insect infestation. Treat as needed.