Jump Right In
Blog Home How To Winterize A Swimming Pool

How To Winterize A Swimming Pool

Categories: How To Guides, Winterizing, Chemicals, Filters, Maintenance & Upkeep, Safety, Pumps, Above Ground Pools
Yes, we know that how to close your swimming pool for winter is the last thing you want to think about! But as we all know, the chilly months always sneak up quickly in the fall and we want to ensure we have this resource out there for you when the time comes.The main reason one should learn how to winterize their swimming pool is to protect it from damage due to freezing water. There’s also incentives such as keeping it as clean as possible for the next season and maintaining its value over time. Knowing how to properly close your swimming pool can save you a lot of money and work when the next swim season comes. Usually, winter is not the time of year that people want to think about their swimming pools but, in reality it is one of the most important times to pay attention to your investment. Properly winterizing your swimming pool will avoid unnecessary problems and costly repairs come springtime. Professional pool companies charge an average of $300-$500 dollars to winterize but, if you are planning on tackling winterization yourself, it is very important to take the time to ensure it is done properly.
1. Clean Out the Pool
The first thing you want to do is clean out the pool. Be it leaves, insects, dirt, debris; anything that’s not water has to go. Either use a pool vacuum, or just fish them out with a net. Don’t forget to clean out the skimmer and the pump basket too. Also, make sure that the tile line is clean. We recommend this tile & vinyl cleaner or a similar product.
2. Balance the Water Chemistry
Balancing the water’s chemistry protects the pool from algae growth, corrosion or scale buildup. Learn more about balancing your pool's water here. Approximately three to seven days prior to closing your pool, make the following adjustments:
  • Adjust alkalinity level between 80 – 120 ppm (parts per million)
  • Adjust calcium hardness level 180 – 220 ppm
Then shock the pool, use chlorine or a non-chlorine substitute to kill bacteria that may be living in the pool. Bring the chlorine level up to 10 - 12 ppm. 
You want to allow the pool chlorine to come down to its normal level, which is about 1.5 - 3.5 ppm, before adding any pool algaecides or pool winterizing chemicals. After that, If you want to add a winterization chemical kit, now’s the right time to do so. Adding winterizing chemicals to your water will help keep it blue and clear for the next season. Always follow the manufacturer’s instructions for the kit. In the case of larger pools, you may be directed to supplement the kit with additional quantities of some chemicals, too. Do not use a floater that contains a strong oxidizer (chlorine or bromine) as the floater will stick against the wall and stain and/or bleach your wall, especially a vinyl liner. For the same reasons DO NOT throw chlorine or bromine tablets into the pool. They will sink to the bottom and damage your pool's surface. If you would like to learn more, check out our blog article on pool closing chemicals.
3. Remove Everything Pool Related
This means skimmer baskets, slides, heaters, wall fittings, vacuums, ladders, pool handrails, pool cleaners or anything else that shouldn't be in the pool. Rinse all of the pool equipment and lay it out to thoroughly dry. Store everything in your garage, shed or any dry place through the winter.
4. Clean and Backwash the Filter 
It's recommended that you do one final brush and vacuum to winterize your swim pool. Once this is done, it's time to clean and back-wash your filter. Do it thoroughly. We have a detailed article on cleaning your filter here. Drain your DE filter tanks and leave the backwash valve open. For sand filters, you need to unplug the filter drain plug and leave off. Put the drain plug with other removed items in the pump basket. Make sure the multiport valve has no water in it. Blow it out with a winterizing blower if necessary. It is not recommended to "acid wash" DE filters at the time of the pool closing. Best time to do that is when you’re opening the pool in the spring so that you can immediately run pool water through the system. Use of muriatic acid on a DE filter and then just rinsing it off and putting it away is another thing you want to avoid doing. The acid may degrade the filter parts over the winter.
Note: This step is not necessary for cartridge filters.
5. Lower the Water Level
If you are closing up your pool for the winter, you should always take precautions to protect it from freeze damage no matter where you live-even pool owners in sunbelt states have learned, to their regret, that freezing temperatures are an ever-present risk. To start the process, drain the water down below the skimmer mouth. Never leave the pool empty. The soil under the pool will expand as the water under it freezes, this can jack the pool right out of the ground; it needs the weight of some water to keep it firmly in place. You can either use your filter pump or a submersible pump to lower your pool water level.
If you're using a mesh cover, lower the water 12 to 18 inches (30.5 to 45.7 cm) below the skimmer. If you're using a solid, floating cover, lower the water to 3 to 6 inches (7.6 to 15.2 cm) below the skimmer. You'll need to lower the level about 4 to 6 inches below the lowest plumbing line, normally the water return line. Be sure the water level is at least below the skimmer.  
6. Drain the Equipment
This is a crucial step of the whole process. Make sure you drain or blow out all the water from every pump, filter, heater and chlorinator or it will freeze and crack. This will ensure all of the water has drained and none is left inside any plumbing lines. Each piece of equipment listed has drain plugs to allow water to drain out. Once you finish draining all the water, remove all D.E. filter grids or cartridge filters and clean thoroughly. If the filter and pump is small enough you should store it indoors. If not, use a pool winterizing blower to blow out any water that may still be in the equipment. Keep the plugs out of these units. Place all the plugs in the skimmer basket during your pool winterization maintenance. By doing this, you'll know where they are when you need them next spring.
7. Cover the Pool
The winter cover is important for both the pool and the people around it. It's stronger than a summer cover, both to withstand the weight of snow and ice, and to protect people or pets from accidentally falling through the cover into the water. It is essential that you find a pool cover that fits tightly. The cover should not have holes or gaps where leaves and debris may enter the pool. For inground pools mesh safety covers provide the highest level of protection and safety. For above ground pools mesh and solid pool winter covers will protect the pool, but are not a safety option. Learn more about choosing a pool cover here.
It’s important to remember that all pools have certain general requirements as well as specific ones due to location, elevation, etc. If you have any doubts about how to close your swimming pool, please give us a call at (888) 836-6025. 
comments powered by Disqus
Related Articles
How To Choose A Pool Cover
How To Choose A Pool Cover
Unless you are one of the lucky few that get to enjoy year round warm weather and pool time, chances are you’ll need to buy a cover for your pool. When you go shopping for a pool cover, here are the major things you’ll want to consider.
Pool Supply Unlimited is an e-commerce company that loves water. We love to pump it, filter it, heat it, chlorinate it, light it up and stare at it while we're barbequing a fat, juicy steak. There are real pool professionals working here. Our guys have seen thousands of pools in their careers, no exaggeration. We are based in San Antonio, TX and can land most products to your door (within the 48 contiguous states) in less than a week.
Visa Mastercard Discover American Express PayPal