Water freezing during winter is one of the greatest problems your pool will encounter. Without the proper winterizing and preventive measures, frozen water can cause severe damages to the pool. It could bust pipes, crack tiles and puncture walls, creating severe leaks that will drain and waste your pool water. We as pool owners naturally do not want this to happen. Maintaining a pool is already difficult and expensive enough. Having to clean and repair damaged pools will prove to be a bigger burden.
The problem with water as it freezes is that it expands. The usually round water molecules crystallize into a larger hexagonal form when frozen. The water increases its mass, thus occupying more space, once it turns into ice. If its container does not have room to accommodate the added mass, the ice will push and force the container to make room for it. This pressure that the ice exerts is what causes the damage. Try freezing the water in a water bottle. If the bottle is made of plastic, it will bloat, stretch and distort. If the bottle is made of glass, it will crack and shatter.
Naturally, there are various measures that can be done to prevent this from happening.
There are anti- freeze chemicals that can be mixed in with the pool water. These however can get quite expensive since you only get to use this once.
A simpler method is to reduce the amount of water inside the pool to create room for the additional mass once it turns into ice. Its drawback? Just consider the amount of water that will have to be spilled and wasted.
Another option is to use a swimming pool air pillow. The air pillow is placed and secured at the center of the pool, under the pool cover. This does not stop the water from freezing; however, it absorbs and directs the pressure of the freezing water toward it instead of on the other parts of the pool. This is will be very effective on the pool itself, but what about the other parts of the pool that is a separate water container. The effect of the air pillow does not extend there.
You can drain and dry the inside of the skimmer then cover it or reduce the water in the pool to a level that is below the skimmer. A skimmer guard gizzmo can also be used. It functions the same way as an air pillow; it absorbs the pressure of the freezing water. The skimmer guard gizzmo is like a narrow plastic tube that can be inserted and secured in the skimmer. It also seals the skimmer entry pipe so that the water does not get into the pipes and filters.
All these methods have their own advantages and limitations. Take time to understand each and do which is affordable and convenient for you.