This is the main type of tank that RainWater Cambodia has been installing due to it's ease of construction and very robust properties. It is also easy to add more tanks to the system later if demand increases or more money becomes available. This is done by connecting the new tank to one of the existing tanks via a small pipe so the tanks are in series, meaning all of the tanks will fill and empty at the same rate. This avoids any confusion created by the use of manual valves and maximises reliability of the system due to a minimum of moving parts and prevents any stagnation of water in the system.
A typical household installation contains four tank stands which hold between 3,000 and 5,000 litres depending on how high we can build each stand (this is determined by the height of the house roof). Often one of the tank stands is built higher than the others to allow the creation of a header tank to create more pressure in the system and if this is done a simple pump is also needed. The extra pressure is typicaly used to supply multiple taps from one tank stand thus increasing the overall benefit to the users. This is particularly appreciated by schools where they might need to supply water to the kitchen, drinking fountains and the toilet blocks. Having water on tap means that the children no longer have to fetch and carry leaving them with more time to learn and play.