In
re-circulating systems, the water/nutrient solution is pumped from a
reservoir to the plant’s roots. The excess nutrient is allowed to drain
back to the reservoir. It is then returned (re-circulated) to the
plants at later feeds (e.g. Fig 5.1). This permits reuse of the nutrient
solution until it is depleted of useful nutrient or is contaminated, etc.
It is then dumped (discarded) and replaced with fresh nutrient.
There are many popular types of
re-circulating systems in use:
- NFT
-
Flood & Drain
-
Aeroponics
- Satellite
