Birdfeeders are to be cleaned every month to maintain a naturally hygienic clean birdfeeder for our feathered friends. Decaying birdseed promotes e-coli bacteria which will harm and in many cases kill birds. Decaying seed also invites parasites that will harm the adult bird and its brew. Cleans away: Decaying birdseed, E- Coli bacteria, Parasites. Effective on: Wood, Plastic, Metal & Ceramic. Can also be used on birdhouses. Makes 33 Gallons.