I made a simple waterer with a 2 gallon bucket upside-down on a pan. I place it 6-8 inches off the ground on a concrete block. The water gets dirty pretty quickly from the girls peaks. They would peck at all sort of things on the ground and then place their dirty mouths in the water. I read in this forum that people change the water every day to keep them clean. If so why bother with a large capacity waterer? I'm thinking the birds pick up all sort of dirty stuff on the ground anyway, what's the point of keeping your water super clean? Is changing the water every 3-4 days OK? How about a week? For those with an automatic waterer (reversed bell shape), how do you keep the water clean? Or you don't?