Algaecide is used to prevent the formation of algae in the pool. It's essential to use ALGASTOP traditional agaecide during the summer, especially during the hottest weeks. In winter, however, when the pool must be covered with a winter cover, it'll be necessary to use WINTER ALGASTOP, the wintering anti-algae, avoiding the proliferation of algae and bacteria. With the algaecide it is possible to prevent the formation of grease on walls and to avoid the green coloring of the water. It's also important to keep the chlorine and ph values at the right level to prevent algae formation. Always check these values and check that the walls of the pool are not too slippery, this would seal that the formation of algae is already underway.