What can I get that would not cost me an arm and a leg for the dogs to swim in?
The only lake around is not clean, and the beach is too far away.
TIA

livestock trough at the feed store or tractor supply?

I was thinking more in a over the ground pool. Any recommendations for this. I just want one big enough for the dogs to exercise.

I would think if you want your dog to swim in someone's "over the ground pool" you would have to have a very good friend you could ask for this favor. You must be some place that is very warm!