HYDROPONICS

 

 What is hydroponics ? >

 The term “hydro-ponics” comes from the Greek words for water and work. It literally means "let the water do the work". Modern applications began in 1930`s. Today, hydroponics commonly refers to growing plants without soil. 

 

Plants do not necessarily need soil, they need mineral elements, water, air, light and warmth. In hydroponics the mineral elements are added to the water to form a nutrient solution which feeds the plants. 

  • This technology has a tremendous future. 

Someday most of our food may well be grown without soil. Thousands of commercial greenhouses around the world use hydroponic systems for growing tomatoes, lettuce and other vegetable crops. Many of those vegetables find their way onto our supermarket shelves. 

  • There are two main categories of hydroponic systems

The active system uses a pump to irrigate the gardens, the passive depends on capillary action or wick absorption. 
Passive systems are not recommended for larger areas. One can achieve good results with house-plants or small salad gardens. However, the rate of growth, ease of maintenance, and overall yield will be very disappointing in bigger gardens or if one is growing vegetables, such as tomatoes. Passive systems are great to start seeds, root cuttings and to get new seedlings going. 
In active hydroponic systems a nutrient solution is pumped from a reservoir onto the plants. Most modern active systems recirculate the nutrient solution. 

There are four main types of active systems:

  • Drip irrigation 
  • Ebb and Flow 
  • Nutrient film technique (NFT) 
  • Aeroponics 


  • Drip irrigation

    • A submersible water pump pushes the nutrient solution from a central reservoir into irrigation tubes where it drips onto the growing medium, drains through it and returns to the main reservoir tank. The emitter regulates how much drips onto each plant. Drip irrigation can be used for commercial applications as well as for house plants.

     

  • Ebb and Flow

    • The nutrient solution is pumped from a central reservoir into the growing medium, temporarily flooding it. The pump is timed, then turned off in order to allow the solution to flow back into the reservoir. Normally a fewl short irrigation cycles are needed a day, more frequent flooding cycles are required on hot days or for large, fast-growing plants. The  “ebb and flow” system is one of  the easiest hydroponic methods to work with and is commonly used in large commercial installations.

     

  • Nutrient Film Technique (NFT)

    • NFT has gained quite some success among commercial greenhouse operators as well as among first-time home gardeners. The roots simply hang in a trough, through which a film of nutrient solution flows constantly. The plants can be supported from above, can be rooted in small plant cubes or can be grown through holes in the trough covering. Some NFT systems use small mesh pots filled with clay pellets to support the plants and to retain moisture around the roots which also avoids that the roots dry out.

     

  • Aeroponics

    • The roots simply hang in the air or inside grow tunnels and are provided with a nutrient solution through a high power pump. There are a number of new systems on the market that provide excellent growth results.

When the system drains the clay pebbles do not compact. They are stable in shape and structure, allowing excess moisture to drain and fresh oxygen to sip in. 

One of  HYDROTONs main advantages is that the pebbles can be cleaned and reused. Some media such as perlite break down after a while, others such as rockwool cannot be used repeatedly because so many dead roots remain in it from previous crops.  

HYDROTON clay pellets are available in various sizes e.g.  4-8mm round, 4-8mm UK ('unround'),  8-16mm round. They are used both for commercial production and for decorative purposes and also as a top layer for pot plants. 

HYDROTON is derived from a renewable and plentiful source (clay) and is therefore considered an ecologically sustainable medium. The clay is formed into pellets and then fired in rotating kilns at 1200°C, which causes the clay to expand like popcorn, creating porous balls. 

HYDROTON pellets are light in weight, do not compact and are reusable - they can be cleaned and sterilised after use. They are also inert, pH-neutral and do not contain any nutrients. 

Because the pellets drain freely and do not hold any excessive water they provide good oxygen levels around the root and are particularly suitable for flood and drain systems. They are also used extensively for rose growing. In drip irrigation systems the pellets can be mixed with a medium with better capillary action to prevent salt build-up. 

HYDROTON pellets are quality tested every two months at the 
University of Hohenheim in Germany.