How to Winterize a Pool

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If you live in an area that drops to freezing temperatures in the winter you will need to winterize your pool. Pool maintenance can take time and energy, but closing your pool does not have to be a headache! We have assembled this easy to follow, step-by-step guide to leave you with no questions on how to wrap up your pool season.

Suggested Items:

pool vacuum, pool cover, pool brush, leaf rakepool gizzmo

Chemical Winterization

This step will help you protect your pool from staining or etching and will ensure a quick and easy opening in the spring! Roughly one week before closing your pool, test the levels of pH, alkalinity and calcium hardness using a water chemistry test kit. Piece of advice: Do not use a floater that contains a strong oxidizer (chlorine or bromine) because the floater may stick against the pool wall and stain or bleach it.

It is always best practice to follow the guidelines of your personal winterizing chemical kit, but the levels almost always fall within:

pH: 7.2 – 7.4
Alkalinity: 80 – 120 ppm
Calcium Hardness: 180 – 220 ppm
Chlorine:  1.5 – 3 ppm

Find a winter chemical kit that contains shock and a winterizing algaecide. Several days before closing, shock the pool with a chlorine shock or non-chlorine shock, using at least 2 lbs per 10,000 gallons. Allow the chlorine level to return to 1.5 – 3 ppm before adding any winter algaecide or your pool cover. If you don’t allow for this time, the high chlorine levels tend to break down both algaecides and pool covers.

Deep Clean the Pool

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The pool should be as clean and clear as possible before covering to make your life easier come spring! As your chemicals adjust, scrub the waterline and remove buildup that could cause damage to your pool cover. Make sure to clean the inside of the skimmer, ridding it of any residue. Give your pool one last vacuum for the season and always use a pool brush to scrub down your cover. Pool covers are porous and need to be cleaned thoroughly to remove particles that could promote staining and algae growth. If you are a little behind on your winterization and already have a large amount of leaves in your pool, we recommend leaf rakes or bag skim nets to remove large amounts of debris. Brush the pool thoroughly after vacuuming. Make sure to remove all add-ons from the pool, such as ladders or skimmer baskets, and store in a dry place for the winter season.

Clean the Pool Filter

Depending on the type of filter you own, this process will be unique for you and your pool. It is always recommended to follow the instructions in your filter’s manual. Before anything else, make sure to clean out the build-up in the filter basket. If you own a cartridge filter, you can soak the cartridge in a filter cleaner. If you own a sand or D.E. (diatomaceous earth) filter, you can backwash your filter.

Lower the Water Level

As water freezes it expands, which can cause great damage to your entire pool system. Lowering your water level will get the water out of the the skimmer which can be easily damaged if water were to freeze there. If you have a sand or DE filter, you can complete this step as you are backwashing your filter. This can be done by setting the pool filter multi-port valve to waste and backwashing the water. If you own a cartridge filter and are not able to backwash to lower your water levels, then you can use a submersible pump. You should lower the water level roughly 6” – 10″ below the skimmer. You can also use a pool Gizzmo to seal the skimmer. It is designed to absorb the expansion of water freezing in a skimmer. The water crushes the Gizzmo instead of destroying the skimmer.

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Winterize the Skimmer and the Equipment

Similar to the skimmer, all water must be drained or blown out of your entire pool system. If this isn’t done properly, then the water could freeze and result in broken piping or equipment. Most of your equipment should have drain plugs that can be taken out to let standing water out. To ensure that all water is out of the lines, you can use a shop vacuum or compressor to blow out any remaining equipment. As the water is blown from each line, you will need to put a plug in the pool end of the line. As an extra precaution, you could add swimming pool antifreeze into the plumbing lines.

At this point, you can disconnect all hoses between your skimmer and filter. If you have a chlorinator, follow the manufacturer’s instructions to winterize and remove the device. The drain plugs need to be kept off of the equipment in the case of water entering the lines. Make sure to take off the pressure gauge because it can be ruined if frozen. We recommend storing the drain plugs in the pump basket and all of the removable equipment in a dry, non-freezing location in your house. You will be able to find them easily for installment in the spring!

Time for the Pool Cover!

You’ve done all the hard work and now all that is left is to simply put the pool cover in place! We recommend using an air pillow to absorb the pressure of freezing water and evenly distribute weight on your pool cover. Similar to the Gizzmo for the skimmer, the air pillows absorb the pressure so that your pool deck doesn’t have to! That being said, make sure to only inflate the pillow to three quarters full so that it won’t pop under pressure.

Make sure that your pool cover is a perfect, tight fit for your pool. Any gaps along the edges may allow leaves or debris into the pool and will ruin all of your hard work to have a clean and clear pool come spring! While you can go with a solid pool cover, we recommend a safety cover because they offer the best protection and can prevent people or animals from falling into the water. Solid pool covers also require a cover pump to remove collected water or snow from the surface. Water bags are used to secure a solid pool cover. These water weights are easier on your pool cover because they distribute the weight and have less chance of causing damage to the cover. If your pool is surrounded by trees that will lose their leaves, we highly recommend a leaf net that can be easily removed once all the leaves have fallen. This will ensure that no extra weight is left on the pool cover over the winter season!

Maintenance of Your Winterized Pool

Your pool is winterized! Now all that you need to do before spring is keep an eye on the amount of water that accumulates on the cover. As mentioned above you can use a cover pump to remove the excess winter water weight if any collects. It is also recommended, but not necessary, to check the chemical balance periodically with a test kit. This will help you avoid any surprises come spring, but if you followed the guide above you have set yourself up for a hassle-free opening in the spring!


  1. Test the chemical levels of your pool and use a winterization chemical kit to prepare it for closure.
  2. Deep clean your pool and pool cover so that your pool is as clean and clear as possible before covering.
  3. Empty the pump basket and clean your filter.
  4. Lower the water level to 6” to 10” below the skimmer.
  5. Remove drain plugs from all equipment, blow out the lines, remove all hoses between skimmer and filter, and store any removed equipment inside for the winter season.
  6. Inflate an air pillow to place under the cover and secure the pool cover over the pool.
  7. Keep an eye on the amount of water that collects on the cover and periodically check your chemicals.

Give us a call at (855) 737-8983 if you have any questions, or if you would like recommendations on winterization products! We would also love for you to leave a comment with any questions or thoughts on winterization in the section below.


  1. I appreciate you giving the exact ph balance and other numbers that I should test my pool water for. This is the first year of owning our pool so we have never winterized it before. I’ll be sure to follow your tips so that it stays in working condition and doesn’t get damaged from the freezing temperatures.

  2. Alex

    Thanks Tristan for your comments. We know you’ll enjoy your pool more in the spring when you get it winterized and ready. Let us know if you have any questions, we are here to help.

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