Algae prevention in waterers 

What brand? I’d like to try this trick for my goats and chickens.

I'm coming over to pet your lovely boy-dog. (heart)

So if I buy black food coloring did you say? And put in five drops it will get rid of the algae in my horses trough? My horses trough is concrete though, will it still work with food coloring. I need to know step by step each process how to do it.

Food coloring is horrible for animals……