Small grow rooms for the beginning hydroponic gardener are usually slightly larger than a closet and can be completely installed in under an hour. The cost ranges from several hundred dollars to over $500, depending on the add-ons that you think you will need. A small greenhouse can cost considerably more because you will need to either include a cement floor and drainage system or lay other types of flooring such as gravel before you build the greenhouse itself. The required nutrients are mixed into the plants’ water supply artificially. The plant roots are suspended within the water by various designs and the crop obtains the food nutrients directly from the water, or from an air mist sprayed directly unto the plant roots. Hydroponics also requires the use growing media. There are two basic divisions between systems: water culture and media based. Systems may also be active or passive. Active systems use pumps and usually timers and other electronic gadgets to monitor the operation. Passive systems may also incorporate any number of gadgets. These systems try not to use pumps and may rely on the use of a wicking agent to draw nutrients to the roots. There is less mess and less maintenance. Hydroponic gardening helps to eliminate the need for weeding and helps to cut down on diseases and pests. This form of gardening is also easily adapted to indoor environments, which means it can be used throughout the year to grow a gardener’s favorite plants. Fuels that contain sulfur or sulfur compounds cannot be used because they produce harmful by products when they burn. Dry ice can be used in small greenhouses, especially if a cooling effect is also desired. Dry ice, which is solid carbon dioxide, is effective when used in a well-sealed area. The ice can either be used in block form or broken down into small pieces and used a little at a time. Pondering the pH Factor in your Hydroponic Garden There are many factors that are important in hydroponic gardening and one of the most important factors is the pH factor. The nutrients, water, trace elements, growing medium, and the gases at the roots have different electrical charges that are all engaged in a constant battle.