Could always just go for a walk and find them in puddles and stuff... And if you did breed them in a bucket I would clear the bucket of them every day, then freeze the ones you can't use, then not only would you not have them turning into adults but you'd have some for winter. I'd stick to one bucket though, I don't think you'll need more than one really. I fed my bettas them but I could only feed them a few at a time, because if they didn't eat them they would have turned into adults in my house. And running water will kill them, so if you have a power filter I don't think you'd have to worry about it. Just my thoughts and experience, I'm gonna go hide in the corner now in case I get bashed...
