The Poolsonic is a powerful algae killer. It is capable in specific circumstances to keep ponds and swimming pools free of algae. In course of time it will also remove the biofilm (a greasy layer on the wall of the swimmingpool). In normal circumstances thee Poolsonic can cope with pools and ponds up to 20 m length. When but the algae pollution is extreme or there are obstacles like plants or little islands or when the water is shallow the distance has to be estimated shorter. The device is not harmful for fish and breed. With swimming the chloor-addition can be reduced with 2/3. Optional the transducer can be replaced by a embeddable transducer.