Simply put, hydroponic gardening is a method of growing plants, without soil, by providing food and water directly to the roots of the plant. By doing so, we eliminate the need for the root system to look for food and water, so the energy normally used by the plant to search for food is used for faster upward growth and fruit production.

Since we don't have competing root systems, we can grow significantly more plants using hydroponics in a given area than those grown in soil. In addition, we recirculate the water and nutrients, so hydroponic gardening ends up using a fraction of the water, with no fertilizer run-off.

There are several types of hydroponic systems, but they all accomplish the same thing, bringing the food and water to the roots of the plants. The most popular hobby hydroponic methods are Passive, Ebb and Flow, NFT or Nutrient Film Technique, and Aeroponics.

In a passive system, plants sit directly in the nutrient solution and the nutrient solution is oxygenated with an aquarium air bubbler so that the roots don't rot. This is the simplest form of hydroponic gardening.

An ebb and flow system has a separate nutrient reservoir with a growing tray directly above. A submersible pump in the reservoir, (like the ones used in ponds), is connected to a fill and drain fitting in the growing tray. The pump is plugged into a timer, which automatically waters the plants in the growing tray 3 or 4 times a day for a few minutes each watering. When the watering cycle is finished, the solution drains back into the reservoir, pulling oxygen into the plant's root system.

Nutrient Film Technique is a system that utilizes sloping gutters or PVC pipe. The plants sit evenly spaced in the gutters and a continuous stream of water and nutrients are pumped into the high side of the gutter. The stream has to be very shallow, no more than 1/8 of an inch deep or so. What happens in NFT is that the roots spread out and intertwine along the bottom of the gutter. The roots in the solution take up the food and water, while those that are growing above the water level take in air and oxygen.

Once you get your system up and running, it will pretty much take care of itself except for some simple maintenance. Once weekly up to 4 or 5 times per month, you will "top off" your hydroponic system. This means that you will replace the nutrient solution that your plants have used with additional, solution.

Learning to pronounce the word 'hydroponic' correctly! Seriously, while hydroponic gardening may sound like rocket science to many, it is a very easy to master this method of gardening.

Even though we have eliminated the soil, plants still require a place for their root systems to develop. A hydroponic media is an inert substance that can provide some support for the root system that has no nutrient value. Almost any inert substance can be used. A few examples include sand, gravel, vermiculite, perlite, LECA (lightweight expanded clay aggregate) and rockwool.

Virtually any kind of plant can be grown with the hydroponic method. The most popular hydroponic crops are lettuce, tomatoes, cucumbers and peppers, which you can now buy in many local supermarkets. Most of the cut flowers delivered in the U.S. are now hydroponically grown as well and home gardeners are discovering the benefits of having a cut flower production system on their balcony or patio.

Since we don't have a large, supportive root system, heavy fruiting crops like tomatoes and peppers may have to be trellised, depending on the hydroponic system used and variety. Root crops like carrots and potatoes present a special challenge as well, although while a bit more difficult to grow hydroponically, it can be done and with pretty spectacular results as well.

N = Nitrogen 7-9-5 Nitrogen is the first major element responsible for the vegetative growth of plants above ground. With a good supply, plants grow sturdily and mature rapidly, with rich, dark green foliage.

P = Phosphorus 7-9-5 The second major element in plant nutrition, phosphorus is essential for healthy growth, strong roots, fruit and flower development, and greater resistance to disease.

K = Potassium (Potash) 7-9-5 The third major plant nutrient, potassium oxide is essential for the development of strong plants. It helps plants to resist diseases, protects them from the cold and protects during dry weather by preventing excessive water loss.

pH is a term used to describe the measurement of how alkaline or acidic something is. In the case of hydroponic gardening, it means how acidic or alkaline the nutrient solution or growing medium is. Plant nutrient uptake is what nutrients the plant takes up. How much plants take up is dependent on the solution being within a certain pH range. Most pH ranges are often around 5.5 to 6.2. Hydroponic nutrients developed for the hobbiest are pH buffered for excellent nutrient uptake over a wide pH range, so exact pH control is not critical. However, your plants will grow faster and be healthier if you keep your solution's pH close to the recommended range, 5.5 to 6.2.

With some nutrients, you will find that your pH range is automatically where it needs to be with no adjustment necessary. If you discover you need to adjust the pH of your nutrient solution, you may do so by adding a few drops of pH up or down, then re-testing to make sure the adjustment is complete. Remember, pH adjustment solutions specifically for hydroponic use are very inexpensive and will provide much more stable adjustment than household products such as vinegar or baking soda. Stability is important, because overuse of pH control products can affect your plants, too!

Rockwool

Rockwool for hoticultural use was invented in Denmark by Grodan in 1969. The product is today used extensively world wide. In North America the majority of greenhouse vegetables are grown in Grodan. Stonewool absorbs moisture without holding nutrients, and even when it is completely saturated still retains 20% air for your plants root system. Stonewool products are made from basalt rocks and chalk, which come from the Earth. Mimicking Mother Nature's production of "angel hair" during volcanic activity, the Grodan stonewool manufacturer heats rocks to 1600°C, to create lava. The lava is blown into a spinning chamber, which makes fibers similar to cotton candy. The fibers are packed into mats, from which Grodan cubes, blocks and slabs are cut. Small tufts of fibers are also produced and bagged as "rockwool granulate". The products make excellent use of natural resources: one cubic yard of rock becomes 37 cubic feet of wool!

L.E.C.A.

L.E.C.A stands for Light Expanded Clay Aggregate and is made by baking pure natural clay at 1200 degrees Celsius for 3 hours to create a porous growing medium. Due to the neutral nature (no acid or base/alkaline qualities) of L.E.C.A, along with other properties it is perfect for growing plants, especially indoor plants in hydroponics. L.E.C.A provides an ideal balance of moisture, food and air to your plants. Capillary action on the surface of the lightweight pebbles wicks nutrient solution to the root systems of your plants. Root rot is eliminated due to the space between the pebbles allowing all-important oxygen to get to the roots. L.E.C.A. is often the growing medium of choice of novices and professionals alike.

Perlite/ Vermiculite mix

Perlite and vermiculite have been used for years to amend professional potting soils made from peat moss (called "soilless" mixes or artificial soils because they literally contain no soil) Essentially perlite and vermiculite are used in the horticultural industry because they both provide aeration and drainage, they can retain and hold substantial amounts of water and later release it as needed, they are sterile and free from diseases, they have a fairly neutral pH (especially perlite which is neutral), and they are readily available, non-toxic, safe to use, and relatively inexpensive. As a rule of thumb, perlite tends to last longer, has a more neutral pH, and functions much better in hydroponics, outdoor applications, lawns and gardens (in part because it is stronger). A 50-50 mix of perlite and vermiculite has been found to be a very good hydroponic growing medium.

Coconut Fiber

This is a major step forward in hydroponic media technology. This is the first "organic" medium which offers top-performance in modern hydroponic applications. Coconut fiber offers many unique advantages - it maintains a larger oxygen capacity than the finest rockwool.Coconut fiber is also very high in naturally occuring rooting hormones. It offers superior water holding capacity to rockwool, a real advantage for intermittent irrigation systems.Coconut fiber is not a biohazard or disposal problem like rockwool - it is completely natural and not environmentally aggressive as rockwool is.Coconut fiber contains organic compounds which other hydroponic media lack. Dutch growers are finding that by blending a mix of 50% coconut fiber with 50% Grorox clay pebbles they achieve the perfect organic-hydroponic media. This blend is rapidly gaining favor with the biggest Dutch growers when used in Dutch Pots - a simple but powerful technology.

Oasis Media