Vacuum
A device that uses suction to collect dirt from the bottom and sides of a pool. Most common is a vacuum head with wheels that attaches to a pole and is connected to the suction line. Some automatic pool cleaners fall into this category.

Vinyl Liner
The vinyl membrane that acts as the container to hold the water in one type of pool construction.

Water Tubes (Also Water Bags)
Tough PVC tubes filled half-way with water and placed on the edges of a winter pool cover to secure it from blowing and to keep from tearing. Water tubes are available in several gauges and lengths.

Weir (Also a Skimmer Weir)
The small floating door on the side of the skimmer over which water flows on its way to the skimmer. The weir prevents debris from floating back into the pool when the pump is off.

Winch (or Turnbuckle)
A winch or turnbuckle is used for tightening the cable to secure your winter above ground pool cover.

Winter Cover
Any of a number of coverings to secure the pool from freeze damage during the non-swimming months. These can be solid, mesh, or safety covers.

Winterizing Plug
An expansion plug which provides a good seal preventing damage to plumbing lines from freezing during winter months.