Aeroponics is still evolving and there are several different designs that are commercially available. In addition, if you are moderately skilled, at do it yourself projects it is also possible to build a DIY Aeroponics system with materials that can be found at most hardware stores. The common element in all these alternatives is the predominant exposure of the plant's root system to air.
True AeroponicsIn true aeroponics, pumps controlled by a short cycle timer deliver water and nutrients to the roots through sprayers . The roots hang in the air and are moistened with an oxygen rich hydroponic nutrient solution for roughly five seconds every 20 minutes. This cycle varies by the crop that is being grown. This keeps the roots moist while providing a maximum amount of oxygen. In true aeroponics, the plant's roots are also allowed to fully drain while still in a humid, dark environment. This enables the roots to absorb more nutrients without burning than in hydroponics or tradition gardening. This system requires the precise application of nutrients and the correct timing of wet and dry cycles. There are 2 approaches to this design:
- Low pressure systems use nozzles similar to a sprinkler system or hose to spray nutrients directly on the roots. These spray nozzles are connected by PVC pipes.
- High pressure systems use a fogger/atomizer that reduces the size of the droplets of solution to a fine mist. This is similar to the misters that you may see used to cool off patrons at outdoor summer events or to keep fruit and vegetables moist at a produce stand.
High pressure systems are more expensive but provide better distribution of nutrients avoiding potential dry spots on the roots as they grow. The drawbacks of true aeroponics is that in the event of a power outage or equipment failure the plants can be severely damaged or die within several hours. In addition, very high quality nutrient solution must be used to avoid clogging the sprayer heads. A true aeroponics design can handle the largest plants and provide the best growth rates but also the require the most expesrtise and are far less forgiving then other forms of soilless gardening.
Deep Flow AeroponicsDeep Flow aeroponics is a hybrid of aeroponics and hydroponic methods. The system is aeroponic because it uses misters or sprayers to oxygenate and distribute the nutrients and hydroponic because a riser in the grow chamber prevents all the nutrients from draining so at least a portion of the roots are aways submerged. Systems of this type typically hold about one inch of nutrient in the grow chamber. The advantage of this design is that there is a buffer in the event of a power outage or equipment malfuntion. This "insurance" against potential failures comes at the cost of slower growth and more incidences of root rot and pathogens that are not generally experienced in the true aeroponics.
Bubbler aeroponics is similar to the deep flow desing configured in a bucket. A portion of the roots hang into the nutrient in the bottom while exposed to bubbles from air stones below and/or misters. If misters are not used the flow of bubbles must agitate the nutrient solution sufficiently to saturate the air in the bucket. Like deep flow this design is also exposed to the problems of root rot and pathogens.