E36 - Stock tank pool heated by fire

We build a swimming pool out of an ordinary stock tank. Then we take it a step further and make it a heated stock tank pool. Our firepit is usually burning at night, so why not heat some water in the process?
Here's a diagram of how we did it:
drive.google.c...
Seen in this video:
Farm tractor: RK24 with backhoe from Rural King
Grapple bucket from Titan Attachments
Stock tank pool: 700 gallon / 8 ft. diameter from Rural King
All hardware was bought off the shelf at Lowe's