"Phisherman" wrote in message
...
I have another thought. Yesterday I suggested adding a small fish,
but the fountain looks like cats can easily get into it. Pond snails
are particularly fond of algae, so if you add a few to each dish they
should help remove the algae.

The fish will die when the sun heats the water. If the water is used up by
the birds or evaporates the poor fish will die an awful death. Our bird bath
holds 2 gallons of water and on a hot day the birds will bathe away almost
all of it. I keep ours clean by dumping and refilling it twice a week.