How to Winterize Your Swimming Pool

For pool owners in regions that experience freezing temperatures, winterizing is essential to protect structural equipment. Water expands by **9%** when it freezes, which can crack underground PVC pipes and split pool filters.

Step 1: Balance and Shock the Water

About a week before closing, ensure your pH is between 7.2 and 7.6, and alkalinity is 80-120 ppm. Add a closing chemical kit containing concentrated algaecide and chlorine shock to keep the water clear until spring.

Step 2: Lower the Water Level

Drain the pool water below the skimmer mouth and return jets.
- **Mesh Cover closing:** Drain water **12 to 18 inches** below skimmer.
- **Solid Cover closing:** Drain water **3 to 6 inches** below skimmer.

Step 3: Blow Out the Plumbing Lines

This is the most critical step to prevent freeze damage. Use a commercial air blower to force air through the skimmer, main drain, and return lines until you see air bubbles in the pool. Seal the lines with rubber expansion plugs.

Step 4: Drain and Winterize Equipment

Remove the drain plugs from your pump, filter, heater, and chlorinator. Store the plugs in the pump basket to prevent losing them. If you have a salt cell generator, disconnect it and store it indoors.

Step 5: Install a Winter Safety Cover

Cover the pool with a safety cover anchored into the concrete deck. Safety covers prevent debris accumulation and keep children and pets safe from falling in.

Taking the time to winterize your pool correctly in the fall saves you from dealing with broken lines and costly repairs in the spring.