A swimming pool should not be closed until the outside air maintains a temperature of 65 degrees or less. The colder temperatures will help to prevent any algae growth in your swimming pool water underneath the Winter pool cover. If you live in an area of the country where the outside air temperature does not stay below 65 degrees, or if you do not put a winter pool cover on your swimming pool, you should continue to run your filtration system and sanitize the swimming pool. This will prevent algae growth or other water problems and staining while the pool is not in use.
A swimming pool should be clean and free of debris before the pool closing process is started, and the pool filter should be backwashed or thoroughly cleaned following the pool filter manufacturer ’s instructions.
The pool chemical levels should be balanced using the following guidelines:
- Free Chlorine: 1-3 ppm.
- Combined Chlorine: 0 ppm
- pH: 7.2 - 7.6
- Alkalinity: 80 - 120 ppm
- Calcium Hardness: 200 - 350 ppm
To chemically treat the swimming pool for the winter you should shock the pool water using a chlorine-free pool shock. A non-chlorine pool shock is suggested because this chemical will oxidize all organic contamination in the pool water to prevent algae from growing, without raising the chlorine level. A chlorine based pool shock will drastically raise the chlorine level of the swimming pool, and the resulting gasses which escape from the pool water surface will collect underneath the swimming pool cover. This may damage the underside of the winter pool cover, and damage the vinyl pool liner (if there is a pool liner) exposed above the waterline. The inert ingredients in most chlorine pool shock may also lead to stains or scaling, if added to the swimming pool immediately before the filtration system is shut down and a pool cover is installed. After chlorine-free pool shock has been circulated for 8 hours, a copper-free algaecide or algae prevention chemical should be added to further prevent any algae growth. Click here to shop for quality pool winterizing chemicals at competitive prices.
Disconnect swimming pool equipment if necessary, and drain all water from the equipment following the manufacturer's instructions. If you live in an area with freezing temperatures you should bring as much of the pool filter equipment indoors as possible. If pool equipment will be left outdoors it should be covered to protect it from harsh weather or damage from ice and rodents.
Drain the pool water 6-8 inches below the lowest fitting inside the swimming pool. To prevent ice damage to the pool plumbing, in-ground pool owners in an area with freezing temperatures need to blow all of the water out of the pool plumbing and put a non-toxic pool anti-freeze into the pool plumbing. If you have not ever closed your inground pool yourself, it is strongly suggested that you pay a local professional to close your swimming pool this year. Pay close attention to what he/she does (in particular the process of blowing the water out of the pool plumbing), and ask questions and take notes if necessary.
Use a guard or plug in the skimmer(s) and return line fitting(s) inside the swimming pool to prevent water from entering the plumbing if the water level inside the pool should rise. You can then install your winter pool cover, following the manufacturer's instructions. Unless you own a safety pool cover, your swimming pool cover should not be pulled taught over the surface of the pool water. A safety pool cover (typically found on an inground pool) has straps extending from the edge of the cover all the way around, and these straps attach to anchors sunk into the concrete or decking around the pool. These sturdy anchors allow a pool safety cover to be pulled taught over the surface of the swimming pool, and support the weight of a person should anyone happen to fall onto the cover during the winter.
A standard "tarp like" winter pool cover should be installed so that it lays on the surface of the water inside the pool. A standard winter pool cover should run nearly straight up the walls of the swimming pool to overlap up onto the decking around an inground pool, or overlap over the top rail of an above ground pool to be secured on the outside of the above ground pool. This prevents the winter pool cover from being pulled into the pool by the weight of water, snow and ice that will inevitably collect on top of the pool cover.