Usually, natural sunlight is used, but during the shorter and darker days of winter, many hydroponic gardeners use artificial lights to increase the intensity of light or to expand the daylight length. Different types of artificial lighting are selected for specific plant varieties and optimum plant growth characteristics. Finally, the use of compressed bottled carbon dioxide is the most commonly used way to create the gas in a greenhouse for the desired effect. Large greenhouses have burned hydrocarbon fuels for years in an effort to increase growth in their plants. Examples of hydrocarbon fuels are propane, butane, natural gas and alcohol. It’s vital to choose a nutrient solution formulated for hydroponics. Standard fertilizers sold in garden stores are not generally suited for hydroponics, as they do not contain specific trace elements, which are necessary for a balanced hydroponic formula. Many formulas also contain buffers to help prevent extreme swings in the pH level. Identifying the spider mites will be easier if you use a garden microscope, which will give you a better view of the tiny bugs. Many think using pesticides to eliminate spider mites in their hydroponic gardens is a good idea, but the use of pesticides in hydroponic gardening is discouraged and usually not necessary. Hydroponics was also integrated into the space program as hydroponics easily fit into their sustainability plans. The research for their plans is ongoing. By the 1970’s, scientists and analysts wee not the only people interest in hydroponics. Traditional farmers and eager hobbyists began to be attracted to the virtues of hydroponic growing. 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.