End Product
The final design consists of an adaptation of the highly effective NFT hydroponics system (learn more on the existing technology page) put into a vertical module that can be attached to walls or stand alone in confined areas of the slums.
The highlight of this design is its versatility and its ability to be adjusted to each contextual constraint. The height of the growth module can be adjusted to receive more light for growth or shelter the plants from the heavy monsoon storms.
The vertical set up means it takes up the smallest amount of the little space available and allows the nutrient solution to flow automatically through all the plants roots. Finally the design ensures that it can be used efficiently and easily by people with different abilities. Children and women can easily adjust the height of the growing plants to suit them.
How It Works
Plants are transplanted into the tubes in the growth module which are made of recycled plastic bottles that are connected neck to end and held by half cut PVC pipes. The plastic bottles are filled with coconut husk as the growth medium for the plants. Water connection between plastic bottles in different growth tubes is made using salvaged plastic tubing. One water container is placed at the top of the system on a separate support or on the roof of the house. Gravity works to drive the Nutrient from the top container through the growth tubes and plants roots at a rate depending on the relative height of the water container to the tubes as well as the angle of the tubes themselves. A second water container is placed at the bottom of the product to collect the nutrient solution that hasn’t been taken up by the roots. This can then be exchanged with the container at the top at time intervals to maintain a constant flow of water. This could also be replaced by a hand pump like the one introduced in the existing technologies section to drive the solution into the upper container. The growth module can then be lifted above the height of the low roofs to receive as much light as possible. This is then lowered for planting, manicuring and harvesting of the plants.
Growth Module
The growth module consists of a frame, holders are mounted onto this frame using a rail system which can be adjusted using bolts and nuts on either side to fix the holder in position. This allows the user to change the amount of growth tubes in the module by adding holders. It also allows the angle of the tubes to be adjusted to vary the rate of flow of the nutrient solution.
This system allows for the growth of different types of plants. Plants with long or short growth cycles can be grown here, plants that need a greater rate of nutrition flow can be accommodated for by adjusting the angle of the tube. For plants that grow taller they can be placed on the top tubing and the space between each tube can be adjusted to provide enough space for each plant to grow.
Reflector
An extra reflector module can be added to increase the amount of light reaching the plants. The frame is made of a combination of plastic lumber wood and recycled aluminum foil as the reflecting surface.
Rope Pulley System
With the use of a rope system which can be aided by counterweights, the height of the growing module can be lifted higher to increase access to light or lowered to shelter the plants from violent storms. This also allows for children and women of different heights to lower the module to the level that suits them. A system of pulleys or simple metal rings can be used to support the rope for the lifting of the growth module
Use of resources and materials
The majority of the design is made using plastic lumber for all the structural parts, The growth tubes are made out of recycled PVC and plastic bottles which are in abundance in the landfills nearby the slum settlements. Most of the other parts are made out of recycled wood, aluminum and metal parts.
The water container system allows the user to reuse the nutrient solution and reduce loss due to evaporation as it is constantly shaded. Coconut husk is available in large quantities on the shores near Mumbai. It is used as a growth medium to support the roots and act as a sponge to suck water and nutrients from the growth tubes to provide them to the roots. A liquid compost maker can be used to transform organic waste into a nutritious liquid compost. This can then be mixed with water to form the nutrient solution.
A pulley system is easily mimicked using metal rings instead as a cheaper alternative.
Above all this design approves of the use of many different materials making the construction of the product versatile and adjustable to the available materials.
Overview
The proposed design has been tailored to fit the context of high density slums in India, this means that it has to be highly versatile to accommodate for the variety and un-orderliness of the slums. It can conform to the shape and form of the existing structures, it is easily built out of recycled materials freely available. With the scarcity of water it reduces loss due to evaporation and encourages the reusing of water over a number of cycles. Incorporating the hydroponics system allows for growth without the use of soil or fertilizers but nutrient solution can be made using liquid compost and water. The use of water containers at different heights means no electric pump is required. The product is safe to use and can be used by people with different abilities. It provides a tool to grow nutrient rich crops that boost immunity and treat symptoms such as coughs and improve general health. The final result is a simple solution to a rather complex problem
