How about this fun duck fact... They don't even have the muscular structure needed to regulate their bowels! SERIOUSLY?! How did this slip past me when I was researching our newest pets?! DOH! You will never be able to get their water as clean as you want it. Good news is;
-OUR idea of cleanliness and A DUCKS idea of cleanliness are vastly different
-wild ducks hang out and raise their young in a fish's toilet. If you're showing a concern, it won't get worse than a fish's toilet.
-when we clean and clean and clean our ducks water, we provide them with hours of entertainment. Both watching us sweat and dirtying it all over again. We're just givers that way.
-the vast quantities of water you dump and the extra money you spend on your utilities are going to help fund some stupid road construction or whatever else your town manages to waste it on. Win/win.
But seriously, there are PLENTY of people who don't do huge ponds or even kiddie pools for their ducks. Ducks don't NEED swimming water to live (again, news to me!) but they sure love it! All they need is something to dunk their head into so they can blow their nose clear. Lots of people have gotten concrete mixing pans from hardware stores and have very happy ducks. When I let ours out to forage while I clean their pen, I fill a tote that's for under the bed. They have a 40gallon
TSC rubber tank in their pen that has a pump and recirculates the water. They're just as happy with the tote.
Think, "easy to handle/move/dump & smallest amount of water required for me to feel like I've provided for them." If you do a kiddie pool, someone here did a study and her 13(?) ducks had no preference between a 3ft or a 6ft pool. She did pro's and con's of each and reccomended the 3 footer.
There are so many ways you can make things easier for yourself. Search the treads like a maniac and ask all the questions you want. There's always someone who has been there, done that, and could talk about their ducks all day. You'll never lack for options!