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How Much Bleach Cleans Algae in a Fountain?

Damien Campbell

No matter how hard you try to keep your fountain clean and attractive, algae is a perennial problem in all fountains. While harmless, algae diminishes the appearance of the water feature. When properly applied, bleach is a useful way to remove algae quickly and easily from fountains. The amount of bleach needed as well as the method of application varies based on the type and size of the fountain.


Algae is easy to remove from fountains with the right bleach solution.

Common laundry bleach is a cheap and easy way to remove algae from water features. Bleach is a readily available cleaning supply and contains approximately 5 percent sodium hypochlorite, a chlorine that effectively sterilizes water. It takes only a mild solution of bleach to remove algae and other microoganisms from fountains. Over time, the chlorine evaporates from the water.

Bleach for Small Fountains

Small garden or indoor fountains made from ceramic or plastic materials are easy to clean by adding bleach directly to the water. Add 1 teaspoon of bleach for every 20 gallons of water in the fountain. For small fountains less than 20 gallons in size, simply add five to 10 drops of bleach to the water. Wipe away the algae from the surface of the fountain a few hours after adding bleach.

Bleach Solution for Large Fountains

Large concrete fountains often require a more concentrated dose of bleach in order to remove algae. Add 3/4 cup of bleach to 1 gallon of water. Drain the water in the fountain and soak the algae with the bleach solution. Allow the solution to sit for 10 to 15 minutes in order to kill the algae and make it easier to remove from the wall of the fountain. Scrub the algae away with a scrub brush and rinse thoroughly with a garden hose to remove the bleach solution and any lingering algae.


While bleach solutions are a simple way to kill algae from fountains, they also contain soaps that remain in the water, and can cause damage to pumps and aquatic animals with regular use. After using bleach to remove algae, limit the amount of direct sunlight the fountain receives, if possible, to reduce the chances of future algae problems.