The word, Hydroponic, comes from Latin and means working water. Simply put, it is the art of growing plants without soil.
When most people think of hydroponics, they think of plants grown with their roots suspended directly into water with no growing medium. This is just one type of hydroponic gardening known as N.F.T. (nutrient film technique). There are several variations of N.F.T. used around the world and it is a very popular method of growing hydroponically. What most people don’t realize is that there are countless methods and variations of hydroponic gardening. In this section, we explain the most common, including the pros and cons of each along with an abundance of great, general information about hydroponics.
That’s simple. If you give a plant exactly what it needs, when it needs it, in the amount that it needs, the plant will be as healthy as is genetically possible. With hydroponics this is an easy task; in soil it is far more difficult.
With hydroponics the plants are grown in an inert growing medium (see below) and a perfectly balanced, pH adjusted nutrient solution is delivered to the roots in a highly soluble form. This allows the plant to uptake its food with very little effort as opposed to soil where the roots must search out the nutrients and extract them. This is true even when using rich, organic soil and top of the line nutrients. The energy expended by the roots in this process is energy better spent on vegetative growth and fruit and flower production.
If you grow two genetically identical plants using soil for one and hydroponics for the other, you will almost immediately see the difference this factor makes. Faster, better growth and much greater yields are just some of the many reasons that hydroponics is being adapted around the world for commercial food production as well as a growing number of home, hobby gardeners.
Growing medium is the material in which the roots of the plant are growing. This covers a vast variety of substances which include Rockwool, perlite, vermiculite, coconut fiber, gravel, sand and many more. The growing medium is an inert substance that doesn’t supply any nutrition to the plants. All the nutrition comes from the nutrient solution (water and fertilizer combined). You can therefore, easily control everything the plants receive. The strength and pH of the nutrient solution is easy to adjust so that the plants receive just the right amount of food. The watering/feeding cycles can be controlled by an inexpensive timer so that the plants get watered on schedule, as needed.
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.
“Hydroponic or Organic-What’s the Difference?” by Roger H. Thayer
The micro-nutrients, also known as trace elements that are required for healthy plant growth are calcium, magnesium, sulfur, boron, cobalt, copper, iron, manganese, molybdenum and zinc. When deficient in any or all of these elements plants suffer stress, disease, become more susceptible to pest, fungus’ and bacteria, and may have uptake issues with the N-P-K fertilizer they are being fed. At best, they will never live up to their genetic potential in growth and yield; at worst, they die. In the case of food crops, nutrient deficient plants lead to nutrient deficiencies in the people and animals who consume them. Due to years of over farming the same fields much of today’s commercially produced food has a nutrient level barely exceeding waxed fruit. No surprise that more and more people are choosing to grow the food their families eat in their own gardens. When growing in soil remember to renew the dirt between plantings and when growing hydroponically know that it is absolutely essential to use a hydroponic fertilizer that provides all the trace elements.
It can be but it doesn’t have to be. Hydroponics can be as incredibly simple as growing a single plant in a hand watered bucket or nursery pot, using any number of inert growing mediums. No automation, electricity or grow lights required.
Of course, the potential to go high tech is limited only by your imagination and budget. Virtually every aspect of garden management can be automated and should you so desire, monitored and controlled with your laptop or cell phone from the other side of the world. Dare to dream.
Most hobby oriented hydroponic systems are somewhere between the two extremes mentioned above. The average, home hydroponic system usually consists of a few basic parts: a growing tray, a reservoir, a submersible pump to water the plants, a simple timer and an air pump and air stone to oxygenate the nutrient solution. Of course, light (either natural or artificial) is also required.
The control of pH is extremely important, not only in hydroponics but in soil as well. Plants lose the ability to absorb different nutrients when the pH varies. (This topic is answered in much greater detail in the “mini-class” on pH in Hydroponics).
The ability to quickly and easily test and control pH in hydroponics is a major advantage over dirt gardening, where testing and adjusting the pH is much more complicated and time consuming.