The perfect storm: why summer is brutal
Almost every green-pool call we get in July and August comes from the same four factors stacking on top of each other. Understanding them is the first step to preventing it.
- UV intensity: Vegas sun destroys unstabilized chlorine in 2–4 hours
- Heat: 90°F+ water lets algae double in population every few hours
- Monsoon dust: Storms drop organic matter that feeds bacteria and algae
- Long days: 14+ hours of sunlight = 14+ hours of algae photosynthesis
The hidden culprit: CYA buildup
If your pool keeps turning green even though you swear you're adding chlorine, your stabilizer (cyanuric acid) is probably too high. Trichlor tabs and dichlor shock both add CYA with every dose, and it never leaves on its own.
When CYA climbs above 80 ppm, free chlorine becomes 'locked' and largely ineffective at killing algae — even at 5 ppm. The only fix is a partial drain and refill to dilute it.
Summer prevention plan
To keep your pool blue from May through September:
- Hold free chlorine at 3–5 ppm (not 1–2 like cooler months)
- Keep CYA between 30–50 ppm — test monthly
- Run the pump 10+ hours a day during daylight
- Brush the walls and steps weekly — algae starts there
- Shock after every dust storm or pool party
- Watch phosphates — high phosphate water feeds algae even with chlorine present
Already green? Here's the recovery
Light green (cloudy, slight tint): triple-shock with liquid chlorine, brush, run pump 24 hours, clean filter. Should clear in 24–48 hours.
Dark green or black: this is a chemical and filtration job that's usually faster and cheaper to hire out. Our Green Pool Recovery service typically returns crystal clear water in 3–5 days, including a filter clean and chemistry rebalance.
Want us to handle it?
We'll diagnose, dose, and dial in your pool — so you don't have to remember any of this.
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