Bob Lowry: Party-Ready Pools and Alkalinity Control

Big bather load on the calendar and worried about cloudy water, itchy eyes, or a long recovery the next day? We brought in legendary chemist and educator Bob Lowry to map out a clean, simple plan that keeps your water clear and your sanity intact. 

We start with the pre-party checklist: raise free chlorine a few ppm, add a measured dose of non-chlorine oxidizer, and keep the pump and filter running. Then comes the sleeper tactic that saves the most money and headache—pre-swim rinsing. Bob explains why sunscreen, deodorant, and lotions burn through sanitizer in the first minutes and how a quick rinse slashes chloramines, improves smell, and protects comfort. 

The conversation then zooms into chemistry that often gets overlooked: cyanuric acid’s hidden impact on water balance. If trichlor is your workhorse, CYA climbs steadily, and your required free chlorine must climb with it—about 7.5 percent of CYA when you’re not using borates. Bob breaks down adjusted alkalinity (carbonate alkalinity), why you subtract about one-third of CYA from total alkalinity, and how a pool can be corrosive even when TA looks “perfect.” If CYA is sky-high, partial drain and refill beats chasing pH and TA forever.

Finally, we tackle a scary test result—pH near 5—and show the controlled fix: use soda ash to nudge pH, baking soda to build alkalinity, and aeration to finish the pH rise without clouding the pool or overshooting. 

• Raising free chlorine and using non-chlorine oxidizer before guests arrive
• Keeping the pump and filter running during and after a party
• Why pre-swim rinsing slashes chloramine formation and chemical costs
• How trichlor drives cyanuric acid growth and chlorine demand
• Using 7.5% of CYA as the free chlorine target without borates
• Adjusted (carbonate) alkalinity and its impact on the saturation index
• Corrosion risks when CYA is high and TA looks “normal”
• Draining to reset CYA to a manageable range
• Lifting very low pH with soda ash, then building TA with baking soda
• Finishing pH rise with aeration to avoid overshooting
• Adding chemicals in thirds and retesting between rounds

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