So this is pretty cool!
You go to your favorite hardware dealer, feed store, etc that deals in large tanks meant to set up troughs for watering animals.
And then you use them as a pool.
Sometimes called hillbilly hot tubs, they're pure genius in my opinion.
Folks are even building decks around them, or putting them in the ground.
Add a pump/filter system and treat regularly and you're enjoying pool life at a fraction of the price.