Perspectives are different frameworks from which to explore the knowledge around sustainable sanitation and water management. Perspectives are like filters: they compile and structure the information that relate to a given focus theme, region or context. This allows you to quickly navigate to the content of your particular interest while promoting the holistic understanding of sustainable sanitation and water management.
This document, rich in pictures, gives a good overview on the history of hydroponics and describes a variety of hydroponic methods and techniques.
DEPARTMENT OF AGRICULTURE SRI LANKA (n.y): Hydroponics. Peradeniya: Sri Lanka: Department of Agriculture URL [Accessed: 21.04.2011]