With an aeroponic system the young plants can be either raised as seedlings using especially designed lattice pots or cuttings can be placed directly into the aeroponic system for rapid root formation. Webbed meshed baskets allow the root system to develop down into the aeroponic chamber or channel where it is regularly misted with nutrient. There is a high success rate with plant cuttings which are rooted in aeroponics - in fact this method has been extensively used as a research tool into root development on many difficult to propagate plant species. The base of the cutting is supplied with high levels of oxygen and moisture in a humid environment which prevents desiccation and accelerates root formation.

Once the young plant has been established into the aeroponics system, the root system rapidly develops in the chamber or channel. What is important at this stage is that the optimum size of the droplets is maintained within the system for maximum efficiency. There is a huge range of aeroponic nozzles so selection of a droplet size range which best suits the plant and system used is fairly easy. Spray droplets less than 30 microns tend to remain in the air as a ‘fog' and are not readily absorbed by the roots. The ideal droplet size range for most plant species is 20 - 100 microns. Within this range the smaller droplets saturate the air, maintaining humidity levels within the growth chamber, the larger droplets 30 - 100 microns make the most contact with the roots, while any droplets over 100 microns tend to fall out of the air before containing any roots.

The Importance of Filtration, Light and Pressure:

 Obviously if a mist of the correct droplet size is to be produced and delivered to the plants, a certain amount of pressure is going to be required - so larger pumps are required in aeroponics systems than would be used in NFT. In order to maintain this pressure, filters need to be kept clean, nozzles free from salts, debris and algae and pumps well maintained. Another important aspect is to ensure the aeroponic chamber is light-proof, growth of algae soon results in blocked nozzles and needs to be avoided. Both inline filters and pump filters assist with removing any particles form the nutrient which might block nozzles, and having sufficient pressure will also assist in keeping nozzles clear and function correctly.

Nutrients:

With aeroponic systems the same inorganic nutrients and methods of ppm(EC) and pH measurement can be used as in other hydroponic systems. However we are now seeing more sediment free nutrients on the market made for aeroponic gardening. When using certain ‘additives' , extra care needs to be taken  - particularly those which are organic in origin. These sometimes contain tiny particles of suspended solid matter which doesn't cause problems in NFT or media systems, but can block the aeroponic micro sprayer.

Temperature Advantages:

If you are constantly battling an overly warm or cool growing environment, aeroponic technology can allow the production of plants which would normally not thrive under certain conditions. By heating or cooling the nutrient before it is misted into the root zone, the temperature inside the growing chamber (which needs to be insulated) can be precisely controlled. Depending on how extreme the aerial environment, it is possible to grow crops with nutrient solution warming or cooling only in aeroponics, something which is more difficult to achieve in other hydroponic systems where the solution rapidly cools/heats as it flows through the system. In Singapore, by cooling the aeroponic solution by 10C(50F) too 15C(59F) below the ambient air temperature, cool season crops can be grown within modifying the temperature of the aerial environment. While this technique is still be investigated it is worth experimenting with on a small scale if hot/cool temperatures are a problem in your growing environment.

Grower Ability:

Perhaps one of the major attractions of aeroponics is the ability to watch the root system grow and develop - plants can be removed from the system and inspected for root damage, diseases, and with crops such as gourmet potatoes being grown in such systems, the process of tuber promotion can also be viewed. Aeroponic technology is progressing at a rapid rate, having the potential for offering faster growth rates and higher yields than most traditional methods of plant production. FHD