Description: Rice husk is a by-product of the milling industry, which is abundant in the rice areas of many countries and offers good properties to be used as a hydroponic substrate. Among its main properties are that it is an organic substrate with a low decomposition rate, it is light, good drainage, good aeration and its main cost is transportation. The main drawback of rice husk is its low moisture retention capacity and how difficult it is to achieve a good distribution of it when used as a single substrate in hydroponic cultivation.