Bird baths need to be cleaned regularly—the exact frequency will vary depending on how many birds use the bath, where it’s located, and the weather, among other factors. In general, it’s best to clean your bird bath whenever you see discoloration in the water or on the bottom of the basin. To clean a bird bath, dump out the old water and remove any large debris. Use a mixture of 1 part chlorine bleach to 9 parts water to scrub the basin, lip, and any areas where birds land, perch, drink, or bathe. Be sure to rinse off the bird bath thoroughly and let it dry before refilling it with clean water.