Types Of Hydroponic Systems

1) Systems categorized by where the roots are located:

• Liquid Culture: The roots are hanging into the nutrient solution which can be either in the form of a liquid or a mist.

• Aggregate Culture: The roots grow into an inert medium such as sand, gravel, Rockwool, perlite, vermiculite, peat moss, foam, coconut coir, etc. and are then irrigated with a complete nutrient solution.

2) Systems categorized by what happens to the nutrient solution:

• Open: The nutrient solution is distributed from a reservoir to the plants and is then “drained to waste” (i.e., not used again).

• Closed: The nutrient solution is distributed from a reservoir to the plants. After passing through the root zone it is collected and reused. In large systems the solution may be analyzed, then modified by the additions of water, acid/base, and/or various inorganic elements to return the solution to the appropriate inorganic mineral composition (and EC) and pH. The solution may also be sterilized (UV light, ozone treatment, etc.) so that any plant pathogens, picked up in the solution from perhaps one or a few infected plants, are not subsequently spread to all of the plants.