Hydroponics is the method of growing, or cultivating, plants in water without soil. Plants get their food from a nutrient solution that is added to the water. Using this method allows you to grow plants in a smaller area than in a traditional soil garden, also making it possible to grow large gardens indoors. The ebb and flow system, also called flood and drain, is one of the most common hydroponic methods.
An ebb and flow system works by flooding a container holding the plants you are growing with a nutrient solution. The container holding your plants sits over another container, which acts as a reservoir for your nutrient solution. The solution is pumped up into the top container through the use of an air pump, which moves the solution through the tubing.
Also attached to the flood and drain system is a timer. The nutrient solution is beneficial to your plants, but only to a point. Exposing the roots of the plant to prolonged contact with the nutrient solution will cause them to burn and die away. The roots should be exposed to the solution no more than 20 to 30 minutes per cycle. The watering cycle will depend on the plant you are growing.
Plants are suspended in the top container by way of a mesh net that allows the roots of the plant to hang down into the nutrient solution, or in mesh pots that allow the nutrient solution to move through the roots. The mesh pots are filled with a growing medium that aids in the absorption of nutrients. Growing mediums commonly used in hydroponics are coconut fiber, oasis cubes, perlite, vermiculite and other soilless mixtures.
A pump, which sits in the nutrient reservoir, pumps the solution up into the top portion of the hydroponic system. As the top fills, the nutrient solution feeds the roots of the plants. Some pumps have a flood drain function, which pumps the nutrient solution up while it is running and drains the solution down when it is turned off. Other ebb and flow systems use an overflow tube that drains the nutrient solution once it gets to a certain level in the top container.
Nutrient solution can be bought from your local garden center or through online retailers. Different plants require specific solutions during different periods of growth. Nutrient solution is usually sold in two ways: as a growth formula for the vegetative growing stage, and as a bloom or flowering formula for when the plant is producing flowers, vegetables or fruit.