How to Close and Winterize Your Pool

Properly closing and winterizing your inground pool will affect how easy it will be to pull back the cover and jump in come spring. The ultimate objectives in closing a pool for the winter months are to:

• Preserve water quality
• Protect equipment and surfaces
• Make ready to enjoy with minimum effort when pool season begins again

Winterizing helps you avoid costly issues such as freeze-thaw damage to pool surfaces, damaged or broken pool equipment, and underground pipe damage. Improperly closed pools can lead to a costly and frustrating opening process. 

When to Start Winterizing Your Pool

Where you live will determine exactly when you need to close your pool for the winter and how vigorously some of these guidelines should be followed. But in general, when your pool water temperature is consistently below 60 degrees, it’s time to start winterizing. There are ten general steps to take, no matter where you live, that will get your pool winter ready. 

1. Address Pool Water Quality Problems

Any water-quality problems should be addressed before your pool is closed. Water problems that are not solved before closing will still exist upon spring opening. In fact, many of these problems can become worse over the course of the winter, which could make spring opening a real challenge. 

For example, a chlorine demand that is not satisfied before closing can continue to grow during the winter, especially in warmer areas.

2. Balance The Water Levels

Addressing water problems can be as simple as balancing your water levels. Water has a natural tendency to seek its own balance (and that could mean taking elements from its surroundings) and this does not stop during the winter months. 

As your pool water gets colder, it naturally becomes more corrosive. Using the APSP standards for testing your water will help you reduce corrosiveness and keep the rest of your levels in check. 

Tip: You’ll want to check your water levels several times throughout the winter.

3. Fend Off Algae Build Up

To help prevent algae growth over the winter months, you will want to use a winter algaecide. Algaecide is a quick, simple and very efficient way of killing off algae. It works with the chlorine already in your pool to make algae cells burst, in turn, destroying the plant.

An algaecide should be added to your pool before shutting down the pump system so it has time to properly circulate.

Tip: If you live in a warmer climate, a mid-winter application may be necessary.

4. Eliminate Pool Stains

All water contains trace amounts of metals like iron, manganese, zinc, silver, aluminum, and copper, which means your swimming pool does too. 

Typically these metals get dissolved into the pool water without issue and cause no harm to you. However, when the chemical levels in the water get out of balance, oxidation can occur which causes cloudy water or stains under the surface. 

A sequestering agent (metal/scale treatment) should be applied to the water to prevent any dissolved metals from staining your pool surface. Metals that may become insoluble during the off season are not being filtered as they would be in season. Sequestering agents will help hold the metals in solution and prevent staining. 

If a pool stains during the winter, it can be several months before it is treated. This would make the stain much more difficult to treat as fresh stains are always easier to remove. Sequestering agents can also help prevent the formation of scale, particularly in hard-water areas. Scale buildup on pool surfaces or equipment can lead to costly repairs. Work with your local pool supplier to get the test and treatment kits you need.

5. Clean

While this might sound obvious, it is imperative to remove any dirt and debris from your pool. Turning on your automatic pool cleaner isn’t enough either. You will want to scrub down pool walls and skimmer baskets. 

Leaves, dirt, and other unwanted debris can cause unsightly staining if left on pool surfaces for long periods of time. These stains will be more difficult to remove months later.

6. Shut Down Pool Equipment

After you’ve scrubbed down your pool and balanced your water levels, you’ll need to turn off the equipment, including timers. Pumps can be damaged by running without proper water flow, so it is important to be sure that the timers are disabled so pumps don’t inadvertently start. 

Be sure to turn off lights as well. The light lenses get hot with the bulbs on and contact with cold water can cause them to crack. You’ll want to remove and store any equipment that may be damaged due to extreme weather conditions.

7. Lower Water Levels and Drain the Lines and Equipment.

Lowering the water levels is an important step, especially for those that live in an area where freezing can occur. As your inground pool water freezes, it expands and lowering your water levels to 4-6 inches below the skimmer will give your pool water the room it needs to expand without causing damage.

You can also add a non-toxic antifreeze to prevent freezing in your pool lines. You’ll want to use an antifreeze that is appropriate for pools, and not automotive antifreeze. 

To drain your water lines, use a shop-vac to blow the water out, then the lines can be plugged to ensure that pipes do not crack over the winter. Alternatively, you can drain the water below the lines in order to ensure that all water is removed from the plumbing. 

Pumps and other equipment should be completely drained by removing the drain plugs. All your water should be removed from the pool filter to prevent damage to the filter housing. You’ll want to be certain there are no open valves that can leak water into the filter.

Should You Completely Drain Your Pool for the Winter?

It is inadvisable to completely drain in-ground pools due to hydrostatic pressure from groundwater in some areas. What that really means is that the water in the soil will freeze and expand. This expansion can cause inground pools to crack or even pop out of the ground. Vinyl lined pools will wrinkle if completely drained and can be very time consuming and costly to repair. 

Close Access to the Pool

Swimming pools are a source of fun recreation and healthy activity, but they can be a safety issue if not secured properly. This includes the winter months when the pool is not being used. 

Children may be curious about a closed pool and pools are less likely to be supervised over the winter, so it is important to be sure that children do not have access. A partially drained pool could constitute a significant fall hazard.

Cover the Pool

Covering your pool will limit the amount of leaves, dirt, and other debris that enter the pool over the course of the winter. Solid covers that fit securely will help minimize unwanted debris, rainwater or runoff from entering the pool. 

If you use a solid cover is, some type of siphon should be used to remove water and other debris that will accumulate on the cover throughout the winter. Keeping the water covered will make spring opening much easier as there will be less debris removal and less potential for issues such as algae and chlorine demand. 

Using a mesh safety cover is a convenient method for keeping leaves and debris, however it will let in rain water. This can affect your water and chemical levels and you’ll want to check those more often to eliminate metal buildups. 

Store Pool Chemicals Properly

Pool products should be stored in a cool, dry, well-ventilated area separate from other products such as fertilizers, motor oil, grease, paint and other household and garden chemicals. 

Mixing these common items with certain pool products can lead to unwanted and potentially dangerous chemical reactions. Keep pool-care products tightly sealed in the original container to prevent contamination. You should always store pool products where they are inaccessible to children and pets. 

It’s best to discard test kit reagents and/or test strips at the end of each pool season. Testing materials have a shelf life, which declines rapidly once opened, and because accurate testing is so important to proper pool maintenance, it is best to start with new test reagents and test strips at the beginning of the next season.

Pool Maintenance Through the Winter

After you’ve completed the 10 step process and properly prepped your pool for the winter, your work isn’t quite done. 

You should continue to check on your pool over the course of the winter. Rain and snow can raise the water level or cause the cover to sink. If this happens, you’ll want to take action immediately. You should also keep an eye out for any heavy debris that may fall into the pool or on the cover and remove it right away. And be ready to properly shock your pool and vacuum before re-opening. You’ll need to keep an eye on your Total Alkalinity as well. Proper off-season care will lead to a much easier spring opening and a more enjoyable pool season.

Whether your pool is completely closed or just put on reduced maintenance, it is important to be sure that the pool is not neglected over the course of the winter. Contact us today if you have questions regarding supplies or any of the steps listed above.