How to prevent mildew in water bucket?

[bigchickie]

I have a bucket watering system and when i looked in it, there is mildew growing. What can I do to prevent this? My chickens thank you!

 

[TurtlePowerTrav]

Wash it out with bleach and rinse it once a week.

 

[Hawgon]

I add acv to my waterers and it works great......

 

[Bear Foot Farm]

Keep it out of the Sun, and add vinegar or chlorine to the water.