Hydroponics is a system by which plants are grown in water without the use of soil. The plants are anchored in an inert medium such as gravel or clay pellets. The roots of the plants grow downward through the medium and take up nutrient rich water, thus eliminating the need for soil.
Three common systems used in hydroponics are ebb and flow, lettuce raft and Dutch bucket. Ebb and flow is made up of a small container filled with perlite or similar medium, a bucket of nutrient rich water and a hose to connect them. The bucket is raised to allow the water to drain into the container of perlite, in which seedlings have been placed. The bucket is then lowered and the water drains back into the bucket. The lettuce raft consists of a piece of Styrofoam cut to fit in a container that is 4 to 6 inches deep and rectangular in shape. Holes are cut in the Styrofoam for net pots, which hold the inert medium and the plant. The Styrofoam floats on top of the nutrient rich water in the container, allowing the roots to be submersed in the water. An air stone is used to aerate the water. The Dutch bucket system makes use of reservoirs. An external bucket acts as a reservoir, from which water is pumped into a bucket that holds the plant. Several buckets can be made to work from the single external reservoir.
The most notable feature of hydroponics is the lack of soil. Plants in a soil garden need the soil to have all the necessary nutrients. If the soil is nutritionally insufficient, the plant dies. In hydroponics, the gardener has control over the type and amount of nutrients individual plants receive. In hydroponics systems, the water is continually recycled and the gardener can renew the nutrients every two to three weeks; this maintains a consistent flow of nutrients to the plants.
There are three different ways to deliver nutrients in hydroponics. Static solution is delivered to the roots via nutrient rich water within the container. The roots sit in the aerated water; a lettuce raft would use a static solutions delivery system. Continuous flow is a system by which the nutrient rich water is continually flowing over the roots of the plants. The plant roots then are not suspended in the water as they are in a lettuce raft, but rather are continually washed with moving water. This is used in large commercial hydroponics farms, but the Dutch bucket system is similar in delivery. In aeroponics, the roots are misted with the nutrient rich solution. The water is in the same container as the plants, but the roots are not in the solution. A basic misting system is employed to create a kind of nutrient rich fog that keeps the roots moist and fed.
Hydroponics gardens take up less space than soil gardens and can be located on a porch or patio or inside the home. They require less water than soil gardens, as the water is recycled through the systems. Hydroponics gardens are less susceptible to disease and pests; soil born pests are virtually non-existent in a hydroponics garden.
For the average gardener, the initial cost of starting a hydroponics garden should be a consideration. A hydroponics kit, complete with nutrients and “hardware” could run as high as $300. Enclosed environment kits can run as high as $500; these systems provide a tent-like structure to enclose the growing systems. But anyone can set up basic hydroponics systems for considerably less money. A basic understanding of pipe, pumps and gardening should provide a sufficient background to develop an inexpensive hydroponics garden.