DIY Pool Heater using an old PC case, Webasto Thermo Top C from a Citroen C8, 12v power supply from a Playstation 3, a thermostat from eBay and old lawnmower fuel tank from eBay and a couple of relays. <br /> <br />This gets my 10ft quick set garden pool from 17'c to 34'c in 24 hours. Much quicker than my 3kw electric heater :-)