Wait… Is This Normal in Your Pool?
Pool owners often ask the same question in different ways: what’s normal in pool water, and what signals trouble. The hard part is that clear, blue water can still have problems that don’t show up until the chemistry collapses. A classic example is chlorine that drops to zero in 24 hours. That can be normal during summer, but only when you understand the relationship between free chlorine and cyanuric acid (CYA). If CYA is high, the pool needs a higher free chlorine level to stay protected. Add in intense sun and UV index, and a “normal” looking pool can burn through a low chlorine residual fast, especially while invisible microalgae is starting to grow. When chlorine seems to vanish, don’t assume the product is bad. Start with the basics of pool maintenance testing: verify CYA, then dose free chlorine appropriately so sanitation keeps up with demand. Also consider hidden chlorine consumers like high phosphate levels, which many standard test kits don’t measure. Phosphates over roughly...