We would have a lot of algae if we did that here in Ohio unless we had some sort of filtering system. I use large buckets of water for my ducks and they get into them and I have to change the water daily and scrub them weekly for algae. I also have to use city water as that is all that I have access to and it has chlorine in it but has never hurt my ducks.I use a 275 gallon poly tank - or maybe 255. I only clean it out once a year.
My kiddie pools I dump and change weekly.