The microbiology of a new recirculatory automatic watering system compared with a conventional automatic system

Continual recirculation and filtration of drinking water prevents the contamination that often mars automatic watering systems by removing algae and fluorescent pseudomonads. Without filtration and recirculation, the algae were clearly visible after 40 days use, and the fluorescent pseudomonad count rose from 10(1) to 10(5) per ml after 72 h use.