A new system for testing water quality in developing countries has been developed by scientists in Spain. The system is affordable, simple to manufacture, and easy to maintain. Crucially, for real-world use, it is also portable. The team from the Universidad Politécnica de Madrid point out that non-potable water and poor sanitation are the leading causes of child mortality worldwide. The new system combines an optical turbidimeter, a filtering device, and a bacteriological incubator. It would be relatively easy to add a meter for detecting dissolved salts, a pH meter, and a chlorine meter. The whole system could be powered by a solar cell.