What is the difference between hydroponic, organic and "regular" fertilizers?

Both hydroponic fertilizers and those intended for use in soil contain the three major nutrients, nitrogen, phosphorus and potassium. The major difference in hydroponic fertilizers is that they contain the proper amounts of all the essential micro-nutrients which fertilizers intended for use with soil do not. The plants are expected to find these elements in the soil, assuming that the trace elements are in fact present. Problems can arise for the plants if any or all of the micro-nutrients are not present in the soil or are depleted by successive (or excessive) plantings. Hydroponic fertilizers are usually in a more refined form with fewer impurities making them both more stable and soluble for better absorption. Organic fertilizers, in most cases, are very different than either hydroponic or soil fertilizers both in composition and how they deliver the nutrient to the plants. Organic fertilizers rely on the synergistic action of bacteria and microbes to break down nutritional substances for easier uptake by the plants. Hydroponic and soil fertilizers provide nutrients in a ready-to-use form. While once, they were mutually exclusive, in recent years a number of outstanding organic fertilizers have hit the market in formulations refined enough for use in hydroponics. For more information click on the excellent article below.