Austin Pool Chemistry Almanac

Cedar fever peak, cold water, phosphate risk

• Skim daily — cedar pollen blankets the surface within hours
• Clean filter elements every 2 weeks minimum (pollen loads filters 3× faster than summer debris)
• Test phosphate levels — cedar pollen is a phosphate source that feeds algae when water warms
• Keep pH in 7.4–7.6 window — cold water + high pH = calcium scale

Cedar tapers, oak catkin drop begins

• Continue aggressive filter care — residual cedar pollen still coats surfaces
• Add phosphate remover if phosphate test reads > 500 ppb
• Check stabilizer (CYA) — if below 30 ppm, raise now so chlorine holds when UV climbs
• Inspect pump and heater now, before spring demand ramps

Oak pollen arrives, water warms, algae pressure starts

• Brush walls and steps weekly — algae footholds establish fast once water is 65°F+
• Raise pump runtime to at least 8 hours
• Verify CYA is 30–50 ppm — UV starts burning chlorine faster now
• Flush skimmers and pump basket more often — oak catkin debris is brutal

Late oak, early summer UV, water crosses 80°F

• Maintain free chlorine 3 ppm minimum through daylight hours
• Pump 10 hours minimum — split runtime morning + afternoon if possible
• Acid-wash salt cells if you haven't this year — scale accumulates fast with warm hard water
• Watch pH — Austin Water alkalinity drives it up daily in warm water

Summer proper — UV 9+, heat, daily acid additions

• Pump 10–12 hours — one full turnover per day minimum
• Test chemistry twice per week at a minimum — once if possible daily
• Add muriatic acid on most visits to counter Austin Water alkalinity pushing pH up
• Watch water level — evaporation of 2"/week + splash-out hides actual leaks

Peak heat, peak evaporation, peak calcium concentration

• Test daily if you see bathers — chlorine demand can triple with heavy use
• Top off with filtered or soft water where possible — tap-water top-offs add calcium
• Watch tile line for early scale — starts as grey haze, not visible white
• Sequestrant (EDTA/phosphonate) helps keep calcium in solution rather than on tile

Sustained heat, often hotter than July

• Hold chlorine at 4 ppm minimum — do not let it drop below 2 ppm in summer
• Inspect heater and salt cell for scale accumulation
• Calcium hardness over 500 ppm becomes aggressive — consider partial drain + refill
• Keep CYA between 50 and 80 ppm; above 100 reduces chlorine effectiveness

Heat eases, summer storms wash in contamination

• Test after every significant rain — storm debris and runoff drop chemistry fast
• Begin tapering pump runtime once water drops below 80°F
• Brush walls weekly — algae is still active in warm water despite cooler air
• Plan post-summer equipment service now while demand is low

Oak leaf drop begins, cool water, lower sanitizer demand

• Empty skimmer baskets every 2–3 days — leaf load overwhelms skimmers fast
• Clean or replace filter elements once leaf drop slows (late month)
• Consider a leaf net cover if your pool sits under heavy oak canopy
• Begin tapering chlorine — cold-water algae growth is minimal

Peak leaf drop, pre-winter equipment prep

• Skim daily or install a leaf cover — this is the heaviest leaf drop week of the year
• Inspect freeze protection — make sure the pump kicks on automatically below 34°F
• If not running the pool year-round, plan winterization for late month
• Clean filter thoroughly before winter sets in

Cold water, cedar pollen arrives late month

• Begin aggressive skimming mid-month as cedar pollen arrives
• Maintain chlorine at 1.5 ppm minimum — cold water hides algae risk but does not eliminate it
• Run pump during freeze warnings — do not rely on schedule during cold snaps
• Check heater operation now if you have winter swimmers