How to keep fountain algae free but safe for birds

[HyperFerret]

My fountain has green algae constantly growing on it. I keep cleaning the fountain and rocks but it regrows so quickly. I know it's probably because of the sun beating through the clear water, presenting perfect opportunity for the algae but I'd really like for the algae to be gone.

I was wondering if there was something I could put in the water to keep it algae free yet still safe for the birds. First I asked a plant nursery and they told me to get a Algaecide (sp?) from Walmart. There I could only find Fungicide in the Lawn & Garden department so I looked in the Pets department in Walmart. In the fish section I found a couple of algae products but it specifically stated not safe for humans or domesticated animals. Now I know the birds are not domesticated but figured it wouldn't be good for them either.

The birds love to drink from and bath in my fountain. I don't mind that at all and would like them to continue to use it. Is there anything that will keep my fountain algae free but safe for the birds? I tried to take a picture of it so you can see what's going on.

[img]https://i127.photobucket.com/albums/p154/HyperFerret3/Fountainalgea.jpg[/img][/img]

[applestar]

I've seen a couple of products in pond catalogs. Try a garden center with a large pond section. The product that I'm thinking of is barley straw and barley straw extract.