How do you keep algae from growing in a bird bath?

Rinse it every other day or put in a circulating pump. The pump will only reduce, not rid, the bath of algae. More tips from FAQ Farmers: * I rinse my bird bath at least four times a week. * Scrub the bird bath with a stiff bristle brush, change the water, and repeat as necessary. There are also natural cleaners you can also use in between rinses such as enzymatic products to break down waste and even oxygen based cleaners that will oxidize muck in birdbaths to help clean them. Algae comes about due to sunlight and the moisture in the birdbath. It is not possible to permanently remove the algae without harming the birds. Things such as bleach will kill of the algae but will harm and/or discourage birds from using your birdbath. Algae is a natural process that although is not always beautiful to look at isn't going to harm the birds like many chemicals will. It is easier to just accept the algae rinse it off occasionally when it gets bad and know that it is going to form on anything that is exposed to nature and is wet.