Your hydroponic system can be as simple as a basic hand-watered system or a more complicated system with automatic pumps, lights and timers. It is possible to build a do-it-yourself system to meet every need. These systems are designed for outdoor use, but could be adapted to indoor use with the addition of grow lights.
What you will need depends on the complexity of the system you choose to build, but in most cases you will need: containers for the plants and a container for the nutrient solution, a pH test kit, a growing medium and a nutrient solution designed for the needs of your plants. Automatic systems will need a small pump and timer to deliver the nutrient solution. If you are growing your plants indoors you will need grow lights.
A Simple Wicking System
This simple hand-watered hydroponic system is suitable for beginners who wish to experiment with hydroponics or for classroom use. You will need a clean 5-gallon plastic container for a large plant. Drill a series of 3/8-inch holes in the side of the bucket, about 1 1/2 inches above the bottom. This creates a shallow reservoir for the nutrient solution.
Fill the container with perlite growing medium. Other growing mediums can be used, but perlite is a good medium for beginners. Plant your plant in the perlite. If you are using a plant started in soil, wash the soil away from the roots before planting.
Mix the nutrient solution as instructed on the package. Check the pH and and make sure it is in the acceptable range for your nutrients. Requirements will vary depending on the plant and growing medium you have chosen. Water the plant with the nutrient solution slowly until you see overflow dripping from the holes. Store the extra nutrient solution in a dark container to prevent algae growth.
Continue to water the plant with the nutrient solution whenever needed. The plant will take nutrients up from the reservoir in the bottom. Always use nutrient solution rather than plain water when watering the plant.
A Do-It-Yourself Ebb and Flow System
This system uses two 5-gallon containers, one for the plants and one for the nutrient solution. It works on the same principle as the first, and can be upgraded with a timer and pump to make it less labor intensive.
Drill a hole in the sides of each of the two containers about 1/2 inch from the bottom. Insert a grommet and connector into each hole. Connect the two with a 5- foot length of plastic tubing.
Put several inches of clean gravel into the bottom of one container and cover the gravel with a piece of fiberglass window screening cut to fit the container. The screening will prevent the growing medium from mixing into the gravel and possibly clogging the tubing. Fill the container with perlite or other growing medium. Plant your seedlings in the perlite.
The other container is the reservoir for the nutrient solution. Mix your nutrient solution according to the package instructions and fill the reservoir. Check and adjust the pH if needed. You will need to aerate the nutrient solution with an air pump and air stone--the kind used in small aquariums is sufficient.
Set the container holding the plants onto a platform or table capable of holding both containers. Water the plants by lifting the reservoir onto the table beside the plant. Leave it there for a few minutes until the liquid level rises in the plant container, this is the flow stage. Then return the nutrient reservoir to the floor below allowing the nutrient solution to drain back into the reservoir. This is the ebb stage. Repeat this process often enough to prevent the growing medium from drying out. Automate this process by installing a pump on a timer to pump the solution into the plant container rather than having to lift the container. Since you are reusing your nutrient solution constantly, check the pH of the solution daily. When your solution is half used up, fill the reservoir with water. Once this new mixture is half used, make a new batch of nutrient solution and use the old solution to fertilize your grass, flowers or trees.