Backyard Drinking Fountain

I have an ornamental fountain in my yard that my dog likes to drink. I need to find a solution to keep the algae growing on the fountain. I have used Pond Block, but is toxic to humans and pets. I also tried Algefix, but this does not seem to help. Ideas?

Thank you!

First, clean the fountain. Take a few stems of fresh cut lavender daylilly and some leaves and tie them together and put in the fountain. I know it sounds silly, but I do every summer in my bird bath and it works.

if the fountain is in direct sunlight algae will grow much faster. Scrubbing it periodically with a soft brush is the most non-toxic. If you also have an aquarium and a fish consumption of algae may work until it eats all the algae. Most fountains do not have adequate filtration to maintain fish permanently. Some fish eat the algae (plecostomus, for example) can also become very large (12 ")