You can purchase a BriteTap chicken waterer attachment online. It is made for attaching to an insulated drink cooler (i.e. Igloo) with spigot. You remove the spigot and attach the BriteTap in its place. It is a super easy solution for keeping their water clean.
Tractor Supply now carries a 3 gallon bucket you can hang by its metal bale handle with 4 of the watering tips on the bottom too.
