To winterize an above ground pool, follow these key steps:

1. Remove all pool gear, toys, ladders, skimmer baskets, and accessories. Clean and dry them before storage.
2. Thoroughly clean the pool by skimming debris, brushing the walls and steps, and vacuuming the bottom to ensure it is as clean as possible.
3. Balance the pool water chemistry by testing and adjusting pH, alkalinity, and sanitizer levels to recommended ranges.
4. Lower the water level to about 6 inches below the skimmer or the pool return line to prevent freezing damage.
5. Disconnect the pump, motor, and any hoses. Drain and clean the filters, and store equipment indoors for winter.
6. Add winterizing chemicals such as pool shock (chlorine or non-chlorine) and algaecide evenly throughout the pool to protect the water during winter.
7. Install an inflatable air pillow in the center of the pool to absorb pressure from ice expansion and prevent damage.
8. Cover the pool with a winter or safety cover to keep out debris and protect the pool through winter.

These steps help prevent damage from freezing, algae growth, and contamination, making pool reopening in spring easier and less costly.