Also, the water that is used is used more effectively; in hydroponics, weeds do not steal part of the crop’s water supply. The benefits are not without their costs, however. The environmental good that hydroponics produces with its decreased water consumption is somewhat negated by the amount of energy needed to support hydroponic growing. The protein and enzyme molecules in a plant are structured in very specific shapes in order to catalyze a chemical reaction to build the plant cells. The need reactant molecules to fit precisely into their gaps so all of the negative and positive charges have to line up exactly. Plants are able to change their own cellular pH level to stop or help speed up a certain enzyme reaction. The temperature control units may also come in handy once you decide how many plants you want to grow in your space. The more plants you have the hotter your greenhouse will usually be. A temperature control unit can be set to turn fans or blowers on and off at pre-determined intervals. They can also be set up to open and close air ducts in your greenhouse or grow room. Many hydroponic gardeners use a method of natural prevention called “companion planting.” In companion planting crops are intermixed with plants that act as spider mite deterrents for the primary crop. For example, marigolds may be planted between rows of herbs in a hydroponic greenhouse. This concept has been around for thousands of years and many countries, including China, Holland, Germany, and Australia have used hydroponics for crop production with results that are quite amazing. Hydroponics is proven to have several advantages over regular soil gardening. The growth rate on a hydroponic plant is 30 to 50% faster than a soil plant that was grown under the same conditions. This method is easy to accomplish with few materials – corn sugar, brewer’s yeast, water, a small bottle and a larger container such as a garbage bag or large glass jug. The process is the same as creating a batch of wine, beer or mead. Once the batch has stopped bubbling the fermentation process has ceased and another batch will need to be made in order to continue the production of carbon dioxide.