Frog Leap All-Out is a 90-day algae preventative thatprovides pool owners with a an effective algae killer that will work with the Frog Leap System, keeping your pool algae free for 90 days if proper chemical balances are maintained. All-Out also dramatically reduces your pool’s need for chlorine and keeps your water crystal clear, while reducing the chances of swimmers developing red eye, skin irritation, or swimsuit fading. This product is so good it is backed by a 90 day guarantee by the manufacturer, providing you will little reason not to buy this product.