DH and DS5 went to Costco yesterday. They came back with a massive "paddling pool" (200 x 170 x 55cm). Our back yard is only slightly bigger than that 
It is going to be a PITA to fill in and keep clean, plus we will hardly be able to use it as we live in the North East and it never gets that hot!
I know he meant well, but he never thinks things through!