first week once a day change For a large kiddie pool. As they grow more poop twice a day at two to three weeks 3 times at four, then mine to out. Large kiddie pool takes 5 pads at a time so two boxes is enough to get them out of the house. Also 5 to 7 ducks per brooder.How long do they last you for? I am currently doing large pine shavings over a beach towel in the bathtub and it' basically 1 full changeout every morning & multiple "spot cleans" through the day.