If you have a pool and don't live in the desert, chances are the temperature is a bit too low if you aren't running a heater. But gas heaters are expensive and bad for the environment and solar heaters are also expensive and quite an eyesore. What other option do you have? How about a few adorable lily pads that are inexpensive and heat your pool totally naturally?
The process is simple, as explained by Edward Hujsak in this tutorial and Daniel Busby in the video above. While the tutorials are slightly different in that Edward suggests using a soldering iron and Daniel recomends using an ordinary iron. It's quite possible that the soldering iron is more sturdy and effective, but the regular iron is a lot easier.