SoCal Aquaponics

The production of vegetables without soil is referred to as hydroponics. Hydroponics requires media other than soil, or some structure to support the plant. Water must contain the 13 essential nutrients for plant growth.Hydroponic culture is usually identified by type of support media that is used

: water culture, sand culture or gravel culture.

Water culture is further subdivided into nutrient film technique (NFT), deep flowing channels and Aeroponics.
 

NFT consists of many narrow plastic troughs or gutters in which the plant roots are placed and exposed to a continuously flowing film of nutrient solution. Deep flowing channels are much wider and deeper so that the plant roots are completely suspended in a slow moving stream of water. The plants are supported at the surface with polystyrene sheets. 

In Aeroponics, the plant roots are suspended in air inside an opaque container and sprayed with a fine mist of nutrient solution. Although these media have all been used successfully in integrated systems, fish culture water has some special characteristics that must be considered in the design of the hydroponic subsystem. Fish produce feces that must be removed from the system through sedimentation or filtration. Although these methods remove most of the solid waste, a relatively small amount remains suspended as small (colloidal) particles.

Hydroponic systems that use fine support media for plants, such as sand or gravel, may eventually become clogged with sludge. The roots of plants grown by NFT may become fouled with a blanket of sludge. Excessive sludge accumulation has a harmful affect on plant growth because it blocks the flow of water and creates zones without oxygen. Plant roots need oxygen for healthy growth. Dissolved oxygen is utilized by the roots for nutrient uptake and other vital cell functions.

There are techniques to prevent sludge buildup and maintain adequate oxygen. A false bottom of rigid screen can be used to separate the root growing area from the bottom of deep flowing channels. The rigid screen can also support plant roots in the NFT method or support growth media such as gravel. Settleable solids accumulate on the bottom of the tank under the root zone. If a few fish are placed under the false bottom, their swimming action can keep sludge from accumulating. To maintain adequate oxygen, gravel and sand media can be flooded intermittently, allowing time for the culture water to drain out of the media and draw air (oxygen) into the root zone. Long, deep flowing channels must be aerated at intervals with diffused air delivered through air stones.

The production of vegetables without soil is referred to as hydroponics. Hydroponics requires media other than soil, or some structure to support the plant. Water must contain the 13 essential nutrients for plant growth. Hydroponic culture is usually identified by type of support media that is used: water culture, sand culture or gravel culture.

Water culture is further subdivided into nutrient film technique (NFT), deep flowing channels and Aeroponics. NFT consists of many narrow plastic troughs or gutters in which the plant roots are placed and exposed to a continuously flowing film of nutrient solution. Deep flowing channels are much wider and deeper so that the plant roots are completely suspended in a slow moving stream of water. The plants are supported at the surface with polystyrene sheets.

In Aeroponics, the plant roots are suspended in air inside an opaque container and sprayed with a fine mist of nutrient solution. Although these media have all been used successfully in integrated systems, fish culture water has some special characteristics that must be considered in the design of the hydroponic subsystem. Fish produce feces that must be removed from the system through sedimentation or filtration. Although these methods remove most of the solid waste, a relatively small amount remains suspended as small (colloidal) particles.

Hydroponic systems that use fine support media for plants, such as sand or gravel, may eventually become clogged with sludge. The roots of plants grown by NFT may become fouled with a blanket of sludge. Excessive sludge accumulation has a harmful affect on plant growth because it blocks the flow of water and creates zones without oxygen. Plant roots need oxygen for healthy growth. Dissolved oxygen is utilized by the roots for nutrient uptake and other vital cell functions.

There are techniques to prevent sludge buildup and maintain adequate oxygen. A false bottom of rigid screen can be used to separate the root growing area from the bottom of deep flowing channels. The rigid screen can also support plant roots in the NFT method or support growth media such as gravel. Settleable solids accumulate on the bottom of the tank under the root zone. If a few fish are placed under the false bottom, their swimming action can keep sludge from accumulating. To maintain adequate oxygen, gravel and sand media can be flooded intermittently, allowing time for the culture water to drain out of the media and draw air (oxygen) into the root zone. Long, deep flowing channels must be aerated at intervals with diffused air delivered through air stones.