Pool Care Guides

Winter Pool Chemistry: The Right Way to Dose & Balance

Empire Pools winterizes pools across Long Island with chemistry that stays stable through freezes. Follow these steps to lock in balance, prevent staining/scale, and reduce spring algae so you open clear and fast.

DIY Winter Chemistry Steps
  1. Step 1: Test & Record Current Levels. Measure pH, alkalinity (TA), calcium hardness (CH), free chlorine (or salt output), cyanuric acid (CYA), and phosphates. Take quick photos of readings for reference.
  2. Step 2: Balance pH, TA, and CH for Winter. Target pH ~7.4–7.6; TA 80–120 ppm (vinyl/fiberglass) or 70–100 ppm (plaster); CH ~200–300 ppm (vinyl/fiberglass) or 250–400 ppm (plaster). Adjust in small doses with pump on for even mix.
  3. Step 3: Add a Metal Sequestrant (If Metals Present). If you’ve seen staining or use well/copper plumbing, dose a quality sequestrant to keep iron/copper in solution over winter.
  4. Step 4: Oxidize (Shock) the Water. Use liquid chlorine or non-chlorine oxidizer per label. Circulate 4–6 hours. Avoid shocking at the same time as adding algaecide to prevent neutralization.
  5. Step 5: Add Polyquat 60 Algaecide. Choose a non-copper polyquat 60 for vinyl/salt pools. Dose per volume and circulate 1–2 hours.
  6. Step 6: Enzyme + Phosphate Control. Add a winter enzyme and a phosphate reducer to limit organics and spring algae. Dose per label; allow additional circulation.
  7. Step 7: Turn Off SWG & Protect Cell (If Salt). Clean the cell if needed and power it down for winter; don’t rely on salt generation in cold water.
  8. Step 8: Final Verify & Document. Re-test pH/TA/CH and free chlorine. Note final readings, date, and products used. You’re ready for mechanical winterization/cover.
Tip: Aim to finish chemistry when water temps are consistently < 60°F. Cold water slows chlorine demand and makes winter doses last longer.
What You’ll Need
  • Reliable test kit (pH, TA, CH, FC, CYA, phosphates)
  • pH up/down; alkalinity increaser; calcium increaser (as needed)
  • Liquid chlorine or non-chlorine oxidizer (shock)
  • Polyquat 60 algaecide (non-copper)
  • Winter enzyme and phosphate remover
  • Metal sequestrant (if metals/staining history)
  • Salt cell cleaner (for SWG pools)

Prefer we handle it? Book winter chemistry.

We’ll balance, oxidize, and protect your pool with a winter-safe program that reduces spring cleanup.