The system of growing plants in suspended air like orchids will surprise us no more as we are used to it which is called aeroponics and there is a revolutionized approach to agriculture which though perfected in the 1940s is now gaining ground and big producers are adopting it-Hydroponics. This procedure was publicly introduced in 1929 by William Frederick Gericke, a Professor at the University of California in Berkeley, a technique of producing plants without using soil but it thrives on inactive medium and mineral nutrient solution thru water. The inert medium to carry the plant while suspended in the water are varied ranging from coconut husk or coir, expanded clay, possolanic lassenite, rock wood, perlite, pumice, vermiculite, sand, gravel, brick shards, polystyrene packing peanuts and wood fiber and the most widely accepted and commonly used material are the rock wool.

The use of rock wool is favored on several grounds. One, rock wool is an inactive material which is not drainage free but likewise provides a recalculating system. Second advantage is that it is of light material and pathogens free, contains low cations exchange capacity (CEC) that facilitates the instant availability of water and nutrients. Rock wool which is made from molten rock and created into cotton-candy like fibers is not reduced by microbiological action and transformed into a fibrous medium that is produced in varying sizes and orientations. Third, rock wool which has a higher density level improves the distribution of moisture and nutrients as well as wicking and drives the root to spread out on the other spaces of the medium which benefit the plant to grow faster because of sufficient nutrient being channeled to the planted area of the medium. And fourth, rock wool after usage can be reused again and turned into bricks or into another set of new rock wool again or it may be mix with soil since it is made of natural rocks and a significant amount of fertilizer is still there inside the medium.

After setting on what medium to use, the next important thing in hydroponics is the water as it would be the medium to carry the mineral nutrient solution. In plants too much and little supply of water are both unfavorable and in Hydroponics water distribution or need is being balanced so that excess water is drained and see to it that what is required is provided. The water is also re-circulated or extensively aerated for oxygen generation and to eliminate anoxic levels which generally drown the root system in traditional soil medium. In the traditional system of using soil as planting medium, a gardener must be near perfect to determine the exact water requirement of the plant, because too much water would bar the plant to oxygen access while little water would incapacitate the plant to move nutrients from its root to other parts since the solution is usually in water.

The mineral nutrients solution are dissolved and mix with the water and normally are inorganic and ionic form and are distributed to the plant in a controlled procedure that was studied based on the area and needs of the plant to be supplied.