By draining water from pipes, filters and pumps, the risk of damage from freezing is eliminated. Water left in the pool helps protect the liner and the structure from cold weather damage. A properly winterized pool won't harbor algae and bacteria that can be difficult to deal with next year.
The reason you don't want to completely drain your pool during winter is because the dry, freezing air can cause rips, cracks and tears in your liner. By allowing pool water to cover the liner, you're preventing the liner from drying up and getting damaged.
Never lower the water level more than 18″, doing so can increase stress on your safety cover and cause the cover to rip or pull the anchors out of your deck. If you are using a solid winter pool cover, lower the water level 3–4″ below the bottom of the skimmer opening, unless you're using a skimmer plug.
Be wary of draining your above-ground pool for the winter; the cold weather can shrink the liner even more and make it more brittle. To go easy on your pool's liner, begin refilling the pool as soon as possible after you've done whatever maintenance you need to do.
Timeframe – Never keep your pool drained for more than a day or two. This can cause the ground surrounding your pool's foundation to shift and change, which can cause extensive damage to your pool and the area around it.
Use the same winterizing chemical steps as you would use on any inground pool, including shocking the pool and adding algaecide and stain and scale preventers. You can even buy winter pool kits that include all the chemicals you need in a convenient package.
In general, it is not recommended to fully drain the pool during the winter. Therefore, it is necessary to lower the water level at the close at a certain level. This depends on the type of pool. For above-ground pool, it is best to lower the water up to 18'' below the skimmer.
Gather Your Pool Closing Essentials
Winterizing chemical kit or pH increaser, Alkalinity increaser, Calcium hardness increaser, Pool shock, and Algaecide. Clarifying enzyme supplement (optional, but recommended) Above ground pool skimmer cover. Expansion plugs.
Rain and snow will enter your pool without a winter swimming pool cover, damaging the water and chemicals, like pH, Total Alkalinity and Calcium Hardness. In addition, be sure that your Cyanuric Acid level is up to 50 ppm, to protect your chlorine from the sun.
If the level of groundwater is high (which, in some cases, can be all the time. In other cases, this could be only after heavy rainfall), the pressure can cause the pool to heave out of the ground. On average, a pool should be drained and refilled once every three to five years unless there is an emergency.
Unhook the filter hoses, and store all pool supplies indoors for the winter. Add 1 gallon of shock per 10,000 gallons of pool water and 1 gallon of Winterizing Pool Chemical Agent per 15,000 gallons of pool water. Spread swimming pool covers for above ground pools over pool and secure cable around the perimeter.
Thus, it's essential to protect your skimmer over the winter by preventing water and moisture in general from entering the skimmer - it's a necessary step in winterizing your swimming pool.
Tips for Winterizing an Above-Ground Pool
Always use a pool cover designed for the size and shape of your pool. If the pool has many deciduous trees above it, use a leaf net on top of the pool cover. Don't skip the air pillows/supports for the cover. These unlock the cover from the water in the event of freezing.
When closing and winterizing your pool, it is important to remember to balance your pool water's chemistry prior to closing and don't forget the algaecide. Algaecide is simple and effective, with one quart of winter algaecide typically enough to treat 20,000 gallons of water all winter long.
The antifreeze works best to winterize your pool skimmer line and return line. The water in your main drain line is still free to move, being connected to the water in the bottom of your swimming pool, so antifreeze added here will simply keep diluting further.
Inground Pool Winter Tips and Guidelines
Mesh Safety Cover – If you have a mesh safety cover and a chlorine pool, you'll want to add 2 gallons of liquid chlorine to your pool water every 2 weeks starting 3-4 weeks after we close your pool and until outside temperatures get consistently colder.
To avoid issues such as flooding and drowning the roots of your grass, and causing root rot, pools should ideally not be emptied onto flat ground where there is nowhere for the water to drain.
“Water acts as a stabiliser that weighs the pool down when it's in the ground, so when you take that water out, it could 'pop' out of the ground or cause the walls to cave in,” explains Swimart Regional Franchise Manager, Peter Allen.
Keeping water in the pool helps to prevent the liner from drying out, shrinking and cracking. An empty pool is far more prone to liner wear and damage. Additionally, even with a cover, an empty pool is more at risk for damage from debris.
Plan on closing a pool for the winter once the temperature is regularly 65 degrees Fahrenheit or lower. You may not be using the pool at this point, but if you close it while temperatures are still warm, you risk allowing algae to grow in the closed pool, creating more work for yourself in the spring.