A dirty bird bath can quickly become unappealing to both gardeners and wildlife, often turning murky, smelly, or even slimy in warm weather. However, a penny or two placed in your bird bath can help slow the build-up of algae and grime, keeping the water cleaner for visiting birds.
This is thanks to the small amount of copper released into the water. But, it is a supporting hack rather than a standalone solution. Bird baths still need frequent cleaning, rinsing and scrubbing to stay safe, especially in summer when heat accelerates stagnation and contamination.
