For the last two years, I have filled from garden hose and added 3 bags of wallmart salt, and simply run the intex SWG for 3 hours a day. Perfect water from May until take down in early October. FC usually around 1-2, but pool always crystal clear? What is the benefit of adding Cyanuric acid? I was going to buy some today, but my wife asked the obvious Q - why mess with perfect. I'm worried maybe the Fc is too low at times and although it looks clear, perhaps its not the best.... If I should add CYA, how much at this point?