Changes

* Open waters are subject to cyanobacteria, due to too many nutrients in the water. The start of the rainy season is the most likely time for cyanobacterial proliferation. Cyanobacteria can be harmful to human health and can cause minor disorders such as headaches or lethal deterioration of hepatic functions and promotion of liver cancer. However, the impact of cyanobacteria has largely been neglected in developing countries due to lack of expertise and inefficiency of monitoring programmes (if they exist). For open waters that may be prone to cyanobacterial blooms, a [[Concrete Biosand Filter]] is a good choice due to its ability to remove cyanobacterial toxins. * Other technologies however may be more suitable for mobile communities (e.g. [[Sodis]] or a [[Ceramic pot filter]], depending on turbidity levels).