This type of Aquaponics is the most user friendly, as there are no additional filter components needed and the waste water is delivered to the media bed directly, where the solids and nutrient solution are allowed to permeate the media and plants roots and then return to the fish tank. Media beds are commonly filled with an inert media such as expanded clay pellets or gravel and are 6” to 12” deep. There is a selection of sizes available including 2’ x 2’, 2×4, 3×3, 3×6, 2×4, 4×4, 4×8 and other sizes. The media used should be inert as the composition may affect the water quality by leaching materials into the system. Worms are also use to assist in breaking down the solids that are deposited into the bed. The media is also the source of surface area for bacterial colonization and is usually sufficient for nitrogen conversion.
A media bed is an Aquaponic System that utilizes media such as expanded clay as a foundation for root growth. Water is pumped into a media filled grow bed and then allowed to flow back to the fish tank. This is a hydroponic growing method called Flood and Drain. This timed flow of water allows for the plants to have a consistent supply of nutrient rich water while maintaining high oxygen levels in the root zone.
As the water rises and falls throughout the media, fish waste becomes trapped and slowly settles to the bottom layers of the grow bed. The media filters the solids and colonizes bacteria on its’ surface area. This alleviates the need for a bio-filter or clarifier to be added to the system. As a media bed matures, worms may be added to help further break down solids and waste in the system into condensed slow released nutrients. This allows us to avoid cleaning the media in a balanced system.
Benefits of a Media Bed System: >> Bio-filtration >> Solids filtration >> Plant support >> A home for composting worms >> Mineralization of solidsEase of Use