Growing plants hydroponically provides a grower with the ability to harvest outstanding crops consistently over time. Monitoring the crops is a daily task that requires careful attention to pH levels, as well as to the crop's appearance. Each plant type has its own unique set of requirements. Careful planning is essential to producing the highest quality yield possible.
Hydroponics is the Creation of an Environment
Hydroponics is based on the fact that a plant's roots thrive with a certain amount of nutrients, oxygen and water. Growers buy and prepare nutrient solutions designed specifically for the particular plants they are growing. The solution should provide water and nutrients to the roots while also allowing oxygen to reach them. Nutrient solutions may also flush out gasses that are emitted by the roots in certain growing environments. The pH, or acidity, of the nutrient solution should be consistently monitored and tailored to meet the requirements of the plants. Usually the pH falls between 5.8 and 6.5. Growers use a balance of calcium nitrate and magnesium to control the pH of the nutrient solution. These two chemicals, when dry, react when placed together, and are therefore mixed with water in separate containers. Liquid nutrient solution is also available.
Controlling the Elements
The amount of air required by the roots is of primary concern. Roots die when they are constantly flooded with water. Roots may also die out if there is not enough solution provided to them. The temperature of the solution is important as well, and must be maintained at a safe temperature, which is usually close to room temperature. The environment of the plant above the roots must also be regulated. Lighting must be controlled to emit a part of the spectrum at a predetermined intensity for a certain amount of time. Plants also require a dark period, normally of around seven hours, during each day. The temperature around the plant, when controlled, also contributes to the success of the crop. Temperatures should generally be lower when the light is off, and higher when light is being emitted.
There are three growing systems that are primarily used in hydroponics. The flood and drain method uses a tray to hold the roots of the plant. Roots are suspended in a non-nutritive environment with spaces left for air. Periodically the roots are flooded with nutrient solution, which is then later allowed to drain out. The drip-feed method relies on a continuous drip of nutrients into the root container. The nutrient solution is then collected and re-circulated back into the drip. With the nutrient-film technique, roots are spread out over a flat plastic or glass surface, while a thin film of nutrients runs over the glass. The simplest method for home growers is the flood and drain method. However, this method does require persistent attention, unlike the drip-feed method, which does not require as much attention.
- Hydroponics: Soilless Gardening Explained; Les Bridgewood; 2003