Direct sunlight enables more rapid algae growth. Help minimize algae proliferation by keeping your fountain in a shady or covered area.  If a completely shaded area is not available, a partially shaded area may still help slow algae growth. Also consider placing a cover such as an umbrella or awning in the area near your fountain to help provide shade if no natural shade is available. Once you’ve put your fountain where you want it, fill it with clean tap water, from a garden hose, for example. Then, connect your fountain to a power source by plugging it into an electrical outlet. You can also opt for chlorinated water instead, as it will act as a disinfectant and prevent unwanted biological growth. The best time to start using algae prevention products is right after you have set up or deep cleaned your fountain. Commercial products are available online as well as at home improvement and maintenance stores.   If you are concerned about the health and safety of wildlife using your fountain, look for animal-safe products. Most products found in pet stores and hardware stores will be animal-safe, but it is important to check the labels. Common products include Algae Shield and SeaKlear. If wildlife is not a concern, such as with indoor fountains, a cap of bleach may also work as a preventative measure. Before applying an anti-algae agent to your fountain, check the manufacturer's instructions to make sure that the product you purchased will not damage your current fountain setup. Product instructions will vary by product, but often all you need to do is add the product to the water on a regular basis to the running fountain.
Place your fountain in the shade. Fill your fountain with water and plug it in. Add in a preventative product.