DIY Pool Heater
Yeah… so, this is something we recommend our readers not do, unless you don’t mind accidentally burning the side of your above-ground pool and causing all of the water to gush out. Instead of investing in a pool heater like any non-engineer would do, this person decided to reroute their pool pump to pass over a crude BBQ pit to bring the water up to temp.

The water is then shot into the pool after being raised several degrees. This process repeats itself indefinitely until the pool is swim-ready with warm, comfortable water. But this isn’t the only way you can engineer your own pool heater.