Hydroponics came about after scientist looked more in to plant biology. It took 260 years to figure the whole composition completely, but after studying what all components that makes plants grow we learned to imitate the enviornment. People first ideas were that the plants were eating the soil that they are growing in. But simple exepirments showed that the soil never actually lost any weight from the begining. This idea then lead to adding nutrients to warter and air. Scientist also discovered that plant matter. Consists of 80 to 90 percent water. The rest of the plant make is carbon, oxygen, and hydrogen. Which plants also extract from water and air. In 1860 german scientists discovered that normal plant growth could be reached with out the use of soil. They immersed the plant roots in aqueous solutions of salts. The most important are nitrogen, potassium, calcium, magnesium, and sulfur. The are the main forms of food the second forms are in small quanities which are iron, chlorine, manganese, boron, zinc, copper, and molybdenum. These are the main substances that support hydroponics. Scientist are always left to answer one question, does hydro yeild more then soil? The answers vary for they say if its your first grow then you should try soil for it is more forgiving then the hydro techniques. But if you are a patient maticulous personand can pay attention to detail then hydro might be your style. It is tru that hydro can generate bigger yeilds but you have to have the know how down pack. It can generate bigger yeilds because roots that are regulary bathed in fresh nutrient solution didn’t have to work as hard as ones in soil. The less work the roots have to do is the less work the plant has to do on top side. Also a roots can up take more oxygen in the hydo process. Some hydroponics system will decrease in yeilds due to a high build up of salts in the setup. Salts like calcium and magnesium deposits bond over a period of time to the inner walls of the tubin and slowly leaks in to a fresh calibrated solution. Also nutrient temps can alter your yeild in hydroponics. Since water is a good conductor of heat it can quickly turn the solution to room tempature, Which may cause the plant temp to swing high or low and that very bad in hydroponics. It cause water born pathgens when the temp changes.