Inactive Hydroponic Methods

• As noted by H.M. Resh in his book "Hydroponic Food Production," The Hanging Gardens of Babylon were an example of hydroponic culture.The theory of hydroponics involves growing almost any type of plant in a nutrient solution without soil. An inactive or passive system has no moving parts, allowing plant roots to grow in a solution only, or in an inert medium that draws up water and nutrients like a wick in an oil lamp.

Wick System

• A length of wick or capillary matting is placed inside a pot or plant container and extended down through an opening to a reservoir below holding water and nutrients. The container is filled with an inactive growing medium such as vermiculite, perlite or sand, which holds the top of the wick or matting in place and is set above the reservoir. Mediums such as these have the ability to either hold moisture or add drainage. Reservoirs should be black or another dark color to deter formation of algae. As the end of the wick absorbs the water from the reservoir, it travels to the container above and saturates the medium, watering and feeding the plants.

Classic System

• A jar or container is filled with a nutrient solution, with cotton or another suitable material used to jam the neck, allowing a small plant to poke through with its roots hanging in the water.

Differences Between Passive and Active Systems

• According to Nutriculture.com, active systems rely on a pump to bathe roots in a nutrient solution and to provide aeration. The plant roots are automatically provided with a nutrient solution in quantities in excess of the rate of uptake. Whatever is not used by the plant is drained away, which reduces watering and feeding mistakes. Passive methods have to draw the solution to the roots or involve suspension in the liquid; in these systems the grower has to determine the quantity and ratio of water and nutrients.

Benefits of Inactive Hydroponics

• The benefits of inactive hydroponic gardening can be environmental as well as practical, as less water is needed compared with growing plants in soil, and pesticides are not routinely used. Flowers and vegetables can be grown in small spaces such as balconies.