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. Large greenhouses have burned hydrocarbon fuels for years in an effort to increase growth in their plants. The gardener should also prune the hydroponic plants regularly. The plant might need to be pruned to focus its energy on the remaining shoots. However, pruning is an art and should be performed with care. Damaged or dying roots may also need to be pruned from time to time. Different plants also have different germination and growing temperatures. Boric acid, manganese chloride, zinc sulfate, copper sulfate and iron sulfate can be used in minute amounts in the nutrient solution. Many people who grow their hydroponic plants in a greenhouse will also find that they need the correct amount of carbon dioxide in the air in order for their plants to flourish. 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. Typical beginning tables for your plants include plastic tubs, a child’s swimming pool or fish tank. A gardener can also buy any of the items they need for their grow room from stores specializing in hydroponic supplies. Once you have your grow room or greenhouse set up, you can decide which plants that you want to try and grow. Gardeners will be able to watch the spectacular improvements that growing hydroponically can bring to their garden. Hydroponics has always been an ecologically sound gardening choice. 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.