Signs of air pollution include spotting or twisting of the plant’s leaves, flower and bud fall off, and unusual discolorations as well as poor growth can signal a problem. Remember, plants are affected by the following elements: air, temperature, light, water and pollution. If you take all of these things into consideration when planning your hydroponic garden your plants are sure to thrive under your care. The word hydroponics comes from two Greek words, “hydro” meaning water and “ponics” meaning labor. 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. It uses much less water than conventional gardening and does not erode the soil or add toxins to the environment. Soluble nutrient formulas are re-circulated and used by the plants’ roots, which helps eliminate environmental waste. As many gardeners today are choosing to grow organically, organic crop cultivation in hydroponics has become very popular. Second, the use of dry ice can aid in the production of this gas. Third, fermentation of organic materials creates carbon dioxide. Fourth, the decomposition of organic matter such as compost will create carbon dioxide. 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. Giant strides have been made over the years in this innovative area of agriculture. Throughout the last century, scientists and horticulturists have experimented with different methods of hydroponics. One of the potential applications of hydroponics that helped continue research was for growing produce in non-arable areas of the world. The basic items you need after you decide on either a grow room or greenhouse include a temperature control unit, exhaust fan, heating mats, light fixtures for your blue and red spectrum lights, an aeration system (an aquarium system works well for small gardens), pearlite, marble and Styrofoam work well as a beginning medium and rockwool, oasis or Rapid Rooters.