Swimming Pool Tips and Reviews

Pool pros and owners often trust the two-to-four ppm chlorine guideline, then wonder why algae returns week after week. The hard truth is that cyanuric acid (CYA) drastically changes how much active sanitizer you actually have in the water. Most of the free chlorine binds to CYA, leaving only a small fraction available as hypochlorous acid (HOCl), the form that kills algae and pathogens. At typical pH values, and even at modest CYA like 30 ppm, roughly 97 percent of chlorine is tied up. That doesn’t mean it’s useless, but it does mean only about three percent is ready to work at any moment, and pH further shifts the HOCl to less potent OCl−. This is why “I have six ppm free chlorine” can still coexist with green walls. The fix is a practical rule that reverses the math: set free chlorine as a percentage of CYA. Rather than chasing a static two-to-four ppm, target seven and a half percent of CYA as your free chlorine level to reliably prevent algae. If CYA is 100 ppm, aim for 7.5 ppm FC...

Winter changes the rules for pool care, and the smartest pros shift with it. As water temperatures fall below 60 degrees, biological activity slows and the familiar algae pressure that dominates summer nearly disappears around 55 degrees. That lull tempts many owners to ignore the water, but chemistry never sleeps. Lower temperature pushes the Langelier Saturation Index downward, nudging water from balanced toward corrosive. When LSI slips, surfaces become the source, and plaster, grout, and heaters can pay the price. The goal in winter is not more chemicals; it is smarter balance with fewer inputs. Less demand does not mean zero demand. It means adjusting set points so the water stays gentle on the vessel while remaining sanitary and clear. The first lever is understanding how temperature affects LSI. A rough field rule is that every 15-degree drop pulls the index by about 0.1. Fall from 90 to 60 and you lose roughly 0.2, enough to turn a barely balanced pool into a surface eater. You...