How To Winterize an Inground Pool

Kenneth Wilson

As summer comes to an end, you want to prepare your inground pool for colder weather. Of course, you can hire someone to handle this task for you. But, you will save yourself a lot of money if you decide to winterize your pool on your own!

There are a few steps that need to be followed carefully and in the correct sequence. However, if you can follow our guide, you will be able to winterize your pool all on your own. Keep reading to find out everything you need to know about the winterizing process. This way you can safely and quickly reopen your pool when the weather warms up again.

When Should Winterize Your Inground Pool?


Before we talk about how you can winterize your inground pool, let’s discuss when you should start this process. Some people like to winterize their pool as soon as summer is over. But, if you want to keep your pool open a little longer, you can wait till the weather starts hitting 65 degrees Fahrenheit regularly. Then you can begin winterizing.

In addition, you don’t want to start too soon. If you begin winterizing your pool and the weather is still warm you can run into problems. For instance, algae could grow in your pool as you wait for certain steps of the process to complete.

So, make sure that the weather is right, and that you give yourself at least a week to do this home project. Then you can begin winterizing your pool.

How to Winterize Your Inground Pool: A Step by Step Guide

The following steps should be done in order and should be followed exactly as we outlined them. This will ensure that the winterizing process is a complete success!

1. Get Rid of Your Pool Ladder and Other Pool Items

The first step is relatively easy. All you have to do is remove your ladder and other pool accessories from your water. This will make it easier to clean and winterize your inground pool.

Begin by loosening your ladder. There should be a bolt or some kind of screw holding your ladder in place. Loosen this with a wrench and then take the ladder out of your pool.  By taking the ladder out now, you will make it easier to cover and clean your pool up later on.

Make sure that there are no cracks, fissures, or loose bolts in the space where your ladder was removed. After this, you can place your ladder aside and store it somewhere safe for winter.

At the same time, you can also begin removing other fixtures and accessories from your pool.

This includes your handrails, skimming basket, your steps, pool cleaners, and other items. Let everything dry off fully, then you can put it away. Make sure your storage area is an accessible place. This way you don’t forget where everything is when spring comes around next year.

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 2. Balance Out Your Water Chemistry

Before you can drain some of the water in your pool, you need to balance out the water chemistry properly. This step is crucial to the winterizing process. So, don’t skip over it. Even though it might seem like a hassle, this will prepare your pool for warmer weather next year.

Ph level is the first thing that you want to adjust and test out. For most pools that are being winterized, you will need a measurement of 7.2 to 7.6 pH. To do this purchase some pH-changing chemicals. You can try out pH Down or pH Up products. There are also products for alkalinity and chlorine levels. 

These can be bought at your local hardware store or online. You also want to get a testing kit that will measure pH, alkalinity, and chlorine.

For alkalinity you want the measurements to read at  80 to 150 ppm. Calcium should also be at between 175 and 225 ppm. Chlorine needs to be stabilized at 1 part per million to 3 part per million, as well.

While you do this organic matter and other debris should be taken out of the pool. And you should let your pool chemicals level out for at least a few days. This will help your pool settle and spread the chemicals evenly in the water.

See You Next Year

3. Clean Your Pool Thoroughly

For this next step, you want to clean your pool much more thoroughly. A vacuum should be used on your pool water first, then use a brush and a skimmer. Your water needs to be free of any biological organism, debris, and dirt. Do this before you lower the water level, as it can be harder to clean your pool with a lower water level. After doing this, your pool should be ready for the next step.

But before you move on, do one last check of your pool. At this point, your pool water should be crystal clear without a trace of anything in the water but your pool chemicals.

This might not seem all that important, but if your pool has anything in it, this can affect your pool chemistry over winter. What this means is that algae and other organisms can invade your inground pool when the weather gets colder.

4. Lower The Water Level to The Correct Level

After cleaning your pool thoroughly, you are going to lower the water level in your pool. How much you lower the water level will depend on what kind of pool cover you have. Anyone with a pool safety cover should lower the water around 6 to 12 inches below the tile of their pool.

If you have a normal solid cover, you just lower it a few inches below your pool skimmer. Really, you don’t want to lower your water level below the 18-inch mark, no matter which type of pool cover you have, as this can cause damage to your pool cover, and even damage the structure of your pool itself.

To further clarify the process, if you have a solid cover that uses a weight, we recommend lowering your water level around 3 to 4 inches below your skimmer. So, make sure you know which kind of pool cover you have, this way you can properly adjust the water level.

You want to lower just the right amount, this is because your cover could collapse and cave into the pool during winter if the water level is not right. Water needs to hold up your cover, but if you don’t follow this step your cover won’t function properly and stay in place during winter.

However, if you have a skimmer plug, you won’t have to worry about this step too much. As the skimmer plug will keep water from escaping into your skimmer.

5. Turn Off The Systems In Your Pool

Once you have the water level lowered to the proper amount, you can begin turning off major systems running in your pool. Start with your pool heater first. How you turn off your heater will depend on what system you have.

If you have a gas heater all you have to do is turn the valve off. This way gas doesn’t heat up the pool water. With millivolt-type heaters make sure to turn off the pilot as well.

More complicated systems like heaters with pressure switches will require drainage along with turning it off. The heater of your pool should be completely drained of water. This way you don’t have issues next spring. Take out the drain plugs to do this and disconnect your pressure switch.

Next, you want to power down your water pumps, lights, and your heater. Do this by accessing your circuit box. You can turn off the timer in your pool if you have one, and any other systems like chemical pumps can be shut down. You don’t want to waste energy on things that won’t be used over winter.

We don`t have to waste resources

6. Fill Your Pool With Winter Chemicals

The next step is one of the most important on this list. Winter chemical kits include pool shock and many other useful chemicals for your pool. Some people choose to pool shock before they balance out the pH. But this depends on what you want to do. If your pool is super dirty and full of algae feel free to shock it before you balance the water out. Otherwise, you can shock your pool while adding in the rest of your winter chemicals.

To begin winterizing your pool, get your winter chemical kit from a store. You can choose one with chlorine or one without chlorine. Personally, we think that chlorine-free kits work better. Once you know what kind of kit you want, make sure that you know the size of your pool. This way you choose the right kit that is the correct size for your pool.

Winter chemical kits include pool shock, but you also get anti-algae chemicals for winter, a stain preventer, and other helpful chemicals that will keep your pool clean all season long.

If you are shocking your pool, during this step, make sure that you get a chlorine-free kit. This will prevent problems with your anti-algae chemicals. High levels of chlorine will make algaecide pretty much useless.

Some people choose not to do this step, but you will be protecting your pool by using this kit. So, consider getting a winter chemical kit. In addition, you want to get a kit that is high quality. This way your water is treated and will be fully ready for winter weather.

Finally, you want to give your pool a good 4 to 7 days to settle with these chemicals. So, don’t cover your pool up right away. Other chemicals can also be added during this time.

People with mesh covers can use pool enzymes which will also help with algae. You can also add more anti-algae chemicals close to spring. This will prepare your pool fully for the new year.

7. Drain the Water From Your Pump and Filter

Next, you want to open up your de filters. Your filters should be assessed and fully cleaned during this part of the process. Look for any holes and rips, and then water them down if you see any debris or remnants. Your filters might be a little stained but this is perfectly fine. If there is major damage, replace your filters. Then move to the next step.

If you have cartridge filters, remove these and make sure to clean them off well. With any of your filters, once they are clean you want to put them back in. This way they are fully installed and ready for spring.

Some people like to add antifreeze to their pump system, but this is a very bad idea. It can actually damage your pump system so don’t do this. Instead, we recommend that you manually get rid of water in your pump, filter, and other pool equipment. This way it is not damaged, or algae-filled by spring.

After you are done removing water from your filter and pump, you can try blowing the lines. We’ll talk about this in the next section more. But this is a great way to prevent freezing in your pool equipment.

Then once you are done blowing the lines, you can start putting everything back together and sealing up your pump and filter system. Make sure the lids and clamps on this equipment are put on tightly.

Drain Water

Drain Water

8. Blow Your Water Lines

Again, you don’t want to use antifreeze during winter. Instead, to prevent freezing and pool damage, you can do something called blowing the water lines. This is a pretty simple process, all you need is something that can blow out air. A tool with a little more power can be useful, but some kind of blower is necessary for this step. You can even rent one.

All you have to do is point the air at your pool equipment. Anything with pipes like your pump system should be blown with air. Your filter can also be blasted. This will ensure that no water remains in your equipment during winter.

You can also use pull plugs to prevent water from entering your pool systems. A skimmer guard can also be useful for preventing freezing and cracking in your pool equipment during winter.

There are some anti-freezes that are made specifically for pools, but it is up to you if you want to use them instead of blowing out your water line.

9. Fill Your Pool Water Bags and Prepare Your Anchor For Your Pool Cover

Your pool cover is crucial to the maintenance and security of your pool during winter. Personally, we recommend getting a safety cover for your pool, as this is the best and most effective choice. With a safety pool cover you can not only attach water bags to your cover, but you also have anchors that will keep your cover in place all winter long.

This type of cover will keep itself nice and close to your pool at all times. It is also kept right on your pool deck even when your pool is being used. So, it is extremely easy to get this cover out and roll it over your pool when winter comes along. 

Some people choose to use a solid winter pool cover, though, which is perfectly fine. This means that you will need to get water bags for sure, as you don’t have any anchors to hold your cover in place. You will also have to fill up these bags with some water.

Be careful and do not let the water leak or get into your pool space. This can mess up the balanced chemistry of the water. Straps will also be needed to hold down the water bags properly. You might be wondering how much to fill up the water bags though. We recommend filling them up at least eighty percent full.

The water you put in the bags will actually freeze and then expand the bags, which will help them keep the cover on your pool in place more effectively. In addition, consider keeping water out for birds and other animals. This way they do not disturb your water bags and won’t try to drink from them during winter.

If something gets into your water bags, this could cause some problems for you. Animals can deflate your water bags and your pool cover won’t anchor down correctly. Try to watch over your water bags during winter to prevent this from happening. Or get a safety cover instead to prevent this from occurring.

However, there is another option besides water bags that can help keep your pool cover safe and secure. Water bags are fine for solid pool covers, but they are often made of thin material that is easy to penetrate. Aqua blocks, on the other hand, could be a better option for you. These weights are a lot more durable and sturdy than water bags.

They cost more money than water bags, but they last a lot longer, and they offer plenty of value for pool owners. So, look into this option if this sounds like something you could use for your pool. Once you have your pool weights ready or water bags filled, move on to the final step of winterizing.

10. Cover Up Your Pool

This is the final step of the winterizing process. Before you do this, make a mental checklist in your head. Have you put in your pool chemicals, cleaned your pool fully, and turned off all the equipment in your pool? If the answer is yes, then you can move on to this final step and prepare to close your pool for winter.

Some people like to skim their pool one last time. Just in case something got in their pool while they waited for the winter chemicals to settle. This can be good, as you will ensure that your pool water is fully cleaned at this point.  Pool owners should also ensure that their pool cover is clean before they put it on.

You don’t want to waste all that time you spent cleaning by putting a dirty pool cover on your water. Next, you can look at your pool cover and make sure that there are no holes or rips in it. Rips can cause issues for your pool in winter. As your water will not be fully protected. Try to seal any tears that you can. And make sure that the patched-up parts of your pool cover won’t leak water.

After checking over your pool cover, start to secure your cover. Begin by putting some water bags on. This will go on the edges of your pool and will help keep the cover in place. Next, the straps should be put on and anchors can be attached to your pool cover. You usually see anchors with a safety cover. So this process will depend on what type of cover you use.

11. Keep Watch Over Your Pool

Once your cover is put on and safely anchored you should be done. This is not hard to do, just take your time and make sure that every inch of your pool water is covered up for winter. You also want to watch over your pool throughout the colder seasons of the month. This can seem unnecessary, but it can be useful for the safety of your family and your pool.

You never know what could happen as extreme weather starts to happen. This means that you want to clean up the cover during winter and keep water and other moisture away from the cover. You might also want to adjust the straps on your pool cover every now and then if they get loose.

Some people like to use simple solid pool covers that only have water bags. But we recommend getting a safety pool cover which is much more secure. This way no one gets injured or hurts themselves if they accidentally fall on your pool cover in winter. Really, you want everyone on your property to stay away from the pool during winter. This will ensure that nothing goes wrong with your cover.

Kenneth Wilson
August 19, 2021

Kenneth Wilson

Retired contractor. Currently residing in Southwest Florida. Now in semi-retirement, I write and manage this blog focused on helping home owners make savvy decisions when it comes to finding contractors and getting their projects done. I also operate remodeling design service for homeowners.

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