We took our Munchkin from the time he was a baby. They either need to be toilet trained or have swim diapers. However, the therapy pool has family hours that you should call to find out. If it's warm enough for the unheated outside pool, however, that's open to children whenever.
Do you except silver sneakers? If so, is there still a monthly charge
I don't know for sure about the age. It may depend on the location. I would call ahead to the location you go to. I have taken one of my grand children before and he was 9 at the time.
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