Algae is a type of plant that lives in water. It can grow on any surface, but is most common on water bottles. Algae can cause your water to smell bad and make your skin itchy. To clean algae from a 5 gallon water bottle, you will need: -A bucket -Water -A cloth or paper towel -A vacuum cleaner with the hose attachment (optional) -A bucket of ice -The algae will be cleaned off the surface of the water bottle in just a few minutes.