What is Hydroponics?
Hydroponics is the system of delivering nutrients to plants via mineral fertilizer solutions, in water, without using soil as a medium. Hydroponics is quite often considered to be the most efficient for growing in climates which may or may not be the most conducive for the specific crops grown. This is due to the fact that environments in hydroponics grow facilities are generally tightly controlled for maximum efficiency, this is called controlled environment agriculture. With this level of control, growers can produce premium food anywhere in the world, regardless of season and temperature. Growers are able to tightly monitor temperature, humidity, and pH levels constantly while nearly eliminated any pest or disease problems. With pest problems reduced, and exact nutrient levels constantly being fed to the roots, hydroponics has very clear advantages in large and small scale grow operations.
Hydroponic Set Up Variations
There are several kinds of hydroponics setups. With plants grown either with their roots submerged directly in the nutrient solution or suspended in an inert growth medium. When roots are suspended directly in their nutrient solution, the plant is generally stabilized by either neoprene collars in the lid of a reservoir, or with a small amount of inert substrate such as clay pellets. Nutrients can be held in an aerated reservoir with roots directly in the reservoir, this is called deep water culture. Another way to deliver nutrients to the plant is to have a recirculating system, like a nutrient film technique, which is where the nutrients are constantly streamed down a slight incline while the roots grow along and uptake nutrients from the stream. Plants grown in an inert medium such as Rockwool or coco can have their nutrients recirculated, or fed using a drain-to-waste system. There are benefits with both. Recirculating nutrients saves huge amounts of water, with up to a 95% drop in the usage of water. This however, can cause issues due to the fact that nutrients are not all used at the same rate and imbalances are difficult to detect until an issue is visibly noticeable in the plants. Drain-to-waste systems, while using more water also allow for a higher degree of control. This is because every feeding delivered is of fresh, unadulterated fertilizer solution.
Whichever method utilized, care must be taken to know exactly what is being fed to the plants at all times. Electrical conductivity, which measures the concentration of fertilizer solutions, as well as, pH which measures the acidity or alkalinity must be well documented and measured frequently. A plant will be extremely reactive and sensitive to shifts in either of these measurements. Faster growth from well-maintained solutions also means faster deterioration in poorly maintained solutions. This is all because of the plants roots being in direct contact with the soluble solution.
Hydroponic Growing Media
Hydroponic growing media is typically well recognized as soilless growing media. Growing hydroponically achieves faster growth rates because oxygenated water and synthetic nutrients are directly provided to the roots for rapid uptake and usage. This leads to increased production and faster crop turnover. Greater crop production leads to better yields and more harvests year round.
Hydroponic media serves as an anchor for the plants, and aids in air and moisture retention. There are three main types, Rockwool, expanded clay aggregates and Growstones.
The most popular, Rockwool, is an inert substrate of molten basalt rock spun into filament fibers. Grodan is the industry leading brand because of its increased moisture retention and proven effectiveness. It is generally not recommended for reuse.
Popular expanded clay aggregates include Hydroton, Hydrocorn and Plant-It. These are inert substrates, round to irregular shaped pebbles, are pH neutral and increase drainage. These do not compact and thus can be reused.
Growstones are made from recycled glass waste. They weigh less than half of expanded clay, making their portability highly appealing. Due to their very environmentally friendly production source, superior air and water retention, as well as their ease on the body they are quickly gaining popularity.