To begin a hydroponic culture medium, a nutrient solution is prepared in a storage tank by dissolving salt mixtures containing the necessary elements for proper plant growth . Since the plants remove nutrient from the water, the solution is periodically revitalized with the addition of salt mixtures, The acidity level is adjusted. Because of the enormous water uptake by the plants, there is an increase in the sodium-chloride concentration in the water, which is remedied by frequently replenishing the solution in the storage tank.
Although plants may be grown with the roots suspended in a water solution, a variety of other substrates is available. Natural substrates such as gravel, sand, and peat provide support for roots but do not have the nutrients typical of soil. They are used in hydroponic culture with the