The results obtained are related to the fertilizer and the environment, and the cultivation of some cultivated species to give better results. The results of the trials on hydroponic pea, bean and tomato crops at the time of germination and growth for electrical conductivity show that the plants are immersed in the water of potatoes (dilution of bark, coffee waste), the superior electrical conductivity by contribution to the first test because of the presence of the salts. Plants immersed in the infusion of waste allow a greater height of stem compared to the plants plunge into the water because of the presence of a significant amount of mineral salts. The misfortune of hydroponics is to bring together under the same conditions water-saving techniques that produce high nutritional value, and require more nutrients. Products totally devoid of interest, both in terms of nutrition and flavour. Plants always grow well when they need exactly when they need it.