I walked into Leslie's to buy 12.5% chlorine liquid. Standing at the counter, I overheard two customers commiserating over how difficult it was to keep their pool chemistry straight, what with all the conflicting mis-measurements and chemistry correction schemes they were constantly being sold. I couldn't help making my next move. While the sales rep was in the back, I took a Leslie's card from the counter, wrote troublefreepool.com on the back, and wordlessly handed one to each guy. I hope they at least visit the site and convince themselves it isn't a cult.