Lord knows.. I have had enough of them.. NO, there is nothing and still be animal(and BIRD) friendly. One just has to empty it each monty or sooner.... splash it with chlorine water to kill the algie... soak up the water/chlorine mixture and then refill. UNLESS you have a charcoal-type filter installed when you have the fountain so that the water recirculates thru the charcoal filter.. then.. everything would be kool.

Smidgen of chlorine aught to do the trick. A little won't kill anything, but it will keep it pretty clean. It also helps to change the water every few weeks. That way you won't keep adding more chlorine and make it super strong.

Just a little clorine can help and it won't hurt animals. One oz. or capful to about 1 1/2 gallons should do the trick.

I use 1 cap full of bleach in my bird bath. I got this idea from birds and bloom magazine. That small amount will not hurt the birds and helps to keep the water clear and the algae from growing