Are algae control products that people use in fish tanks harmful to birds?

We have a bird bath in our back yard and it often gets algae build-up in it. We try wiping it out but it always comes back. If we used the tablets that people use in fush tanks, could it harm the birds that bathe in and drink from the bath? Does anyone have any other suggestions?Are algae control products that people use in fish tanks harmful to birds?
If you mean what you put in your toilet by flush tank then I would not recommend putting that in water any creature would drink.Are algae control products that people use in fish tanks harmful to birds?
The only product out there that I think would be SAFE would be Algaefix by Aquarium Pharmecuticals and you should be able to find it in a local pet store.