Algae, floating microscopic plants, thrive in sunlight. These plants don't put down roots or flowers, yet they spread quickly in warm conditions. While they provide food and oxygen in a complete ecosystem such as a water garden, algae become eyesores in a water fountain, causing a coating of green slime. Algae blooms -- increased growth -- occur in the presence of excess nutrients, such as decaying plant debris or fertiliser, the Washington Department of Fish and Wildlife reports. Cleaning and maintenance stops algae from taking over your water fountain.
Unplug the fountain pump. Drain the fountain. A wet dry vacuum can help with this.
Remove the fountain pump and put it in a bucket or other container. Pour white vinegar over the pump to cover it. The vinegar loosens the algae and helps to dissolve mineral deposits that keep your pump running smoothly.
Rinse the interior of the fountain basin and scrub it with a stiff bristled brush. If there's a build-up of algae add 1 tsp of white vinegar to a qt. of warm water and scrub off the algae. Rinse thoroughly to remove all the soap.
Move the fountain into the shade, if possible. Sunlight promotes algae growth.
Refill the fountain with fresh water. Rinse the fountain pump under running water. Put the fountain pump back in the fountain.
Add 1/2 cup of white vinegar per 4 gallons of water to help stop algae in your water fountain. Skim leaves and other debris out of the fountain basin regularly to discourage algae.
Soak any rocks or fountain ornaments in vinegar to help remove algae. Clean the water fountain and change the water monthly or at least once every three months to help stop algae growth. Using distilled water helps prevent algae, but isn't feasible for large outdoor fountains. Rainwater is the second best choice for fountain water. Lemon juice also discourages algae growth.
Avoid copper algicides. These products pollute water and harm aquatic life.