IMO, Without the aid of a chemical like chlorine and the risk of permanently hurting your fowl. I don't think you can kill Algae, only slow it down until you properly clean the container.
https://www.backyardchickens.com/threads/algae-and-the-pink-stuff-in-my-ducks-water-dish.1407140/
https://www.backyardchickens.com/threads/algae-and-the-pink-stuff-in-my-ducks-water-dish.1407140/

Seems like an on going issue with no real fix for the problem, just deal with it ! LOL
. It actually worked pretty good because you could bend it but I'd like something longer and a tougher brush.
