he History of Hydroponics
The word hydroponics comes from two Greek words, “hydro” meaning water and “ponics” meaning labor. The concept of soil less gardening or hydroponics has been around for thousands of years. The hanging Gardens of Babylon and The Floating Gardens of China are two of the earliest examples of hydroponics. Scientists started experimenting with soil less gardening around 1950. Since then other countries, such as Holland, Germany, and Australia have used hydroponics for crop production with amazing results.
The Benefits of Hydroponics
Hydroponics is proved to have several advantages over soil gardening. The growth rate on a hydroponic plant is 30-50 percent faster than a soil plant, grown under the same conditions. The yield of the plant is also greater. Scientists believe that there are several reasons for the drastic differences between hydroponic and soil plants. The extra oxygen in the hydroponic growing mediums helps to stimulate root growth. Plants with ample oxygen in the root system also absorb nutrients faster. The nutrients in a hydroponic system are mixed with the water and sent directly to the root system. The plant does not have to search in the soil for the nutrients that it requires. Those nutrients are being delivered to the plant several times per day. The hydroponic plant requires very little energy to find and break down food. The plant then uses this saved energy to grow faster and to produce more fruit. Hydroponic plants also have fewer problems with bug infestations, funguses and disease. In general, plants grown hydroponically are healthier and happier plants.
Hydroponic gardening also offers several benefits to our environment. Hydroponic gardening uses considerably less water than soil gardening, because of the constant reuse the nutrient solutions. Due to lack of necessity, fewer pesticides are used on hydroponic crops. Since hydroponic gardening systems use no topsoil, topsoil erosion isn’t even an issue. Although, if agricultural trends continue to erode topsoil and waste water, hydroponics may soon be our only solution.
The purpose of a growing medium is to aerate and support the root system of the plant and to channel the water and nutrients. Different growing mediums work well in different types of hydroponic systems. A fast draining medium, such as Hydrocorn or expanded shale works well in an ebb and flow type system. Hydrocorn is a light expanded clay aggregate. It is a light, airy type of growing medium that allows plenty of oxygen to penetrate the plant’s root system. Both types of grow rocks can be reused, although the shale has more of a tendency to break down and may not last as long as the Hydrocorn. These grow rocks are very stable and rarely effect the pH of the nutrient solution.
Rockwool has become an extremely popular growing medium. Rockwool was originally used in construction as insulation. There is now a horticultural grade of Rockwool. Unlike the insulation grade, horticultural Rockwool is pressed into growing cubes and blocks. It is produced from volcanic rock and limestone. These components are melted at temperatures of 2500 degrees and higher. The molten solution is poured over a spinning cylinder, comparable to the way cotton candy is made, then pressed into identical sheets, blocks or cubes. Since Rockwool holds 10-14 times as much water as soil and retains 20 percent air it can be used in just about any hydroponic system. Although the gardener must be careful of the pH, since Rockwool has a pH of 7.8 it can raise the pH of the nutrient solution. Rockwool cannot be used indefinitely and most gardeners only get one use per cube. It is also commonly used for propagation.
Other commonly used growing mediums are perlite, vermiculite and different grades of sand. These three mediums are stable and rarely effect the pH of the nutrient solution. Although, they tend to hold too much moisture and should be used with plants that are tolerant to these conditions. Perlite, vermiculite and sands are very inexpensive options, and work charitably in wick systems, although they are not the most effective growing mediums.
Most of the principles that apply to soil fertilizers also apply to hydroponic fertilizers, or nutrient solutions. A hydroponic nutrient solution contains all the elements that the plant normally would get from the soil. These nutrients can be purchased at a hydroponic supply store. Most are highly concentrated, using 2 to 4 teaspoons per gallon of water. They come in liquid mixes or powered mixes, usually with at least two different containers, one for grow and one for bloom. The liquids are the slightly more expensive and the easiest to use. They dissolve quickly and completely into the reservoir and often have an added pH buffer. The powered varieties are inexpensive and require a little more attention. They need to be mixed much more thoroughly and often don’t dissolve completely into the reservoir. Most do not have a pH buffer.
Read more at: hydroponics.net