My 4 Indian runners have a 4 ft kiddie pool in the run. They constantly get it dirty...not from poop or food, but from dirt. They not only swim/bathe in it, they use it to dig in the ground for worms or grubs or whatever. I think what they're doing is they use the water to soften up the ground to search for something yummy. Then when they get something, they hold it in their beak and rinse the dirt off in the pool. I swear the pool is dirty again within an hour of filling it up. I'm on city water, so I have to pay for what I use. I'd like to get them a bigger pond with a filter pump to reduce refills, but I'm guessing the filter will clog right away and I'd be cleaning it multiple times a day, no thanks. Is there some type of pumping system that could help with keeping their pool/pond clean with all that dirt? They do the same thing with the five gallon waterer and get the water dirty and use it up quickly, so it needs to be filled everyday...the poor chickens are always having to drink muddy-looking water. I'm going to put a drip water system in to fix that problem!