How to Winterize a Pool

When to Close Your Pool for the Winter

When temperatures start dropping it’s time to take action to protect your pool. Make sure you follow the correct steps to get your pool ready before you put on your seasonal safety cover and close your pool for the winter. If you have any questions, call your local Latham Independent Builder for help.

It’s important to monitor your pool water temperature to prevent damage to your pool and pool components.

Give yourself enough time and start the process when your pool water starts to drop. Freezing water can expand and cause damage.

Follow these steps to protect your pool and keep everything in working order for when it’s time to open your pool in the spring. Note that there is also a set of steps below to take if you live in a milder climate but will be using your pool less over the winter. When in doubt about any steps in the process, contact your Latham pool dealer.

What You’ll Need to Close Your Pool for Winter

Besides a swimming pool cover, you’ll need some items, like tools and chemicals, to maintain your water, prevent freezing, and get your pool ready for winter.

Tools & Equipment to Close Your Inground Pool

These tools will help you prepare your pool for the winter months when your pool is not in use. If you’re not sure how to use this equipment or don’t want to buy more supplies, contact a pool technician.

Basic tools: Screwdriver, wrench, a ratchet set, to remove ladders and other pool accessories
Wall brush
Leaf net
Air blower: This is very important. Make sure to use an air blower like a liner vac, with high volume and low pressure
Seasonal safety cover
Pool vacuum

What Chemicals Do You Put in Your Pool for Winter?

You will also need a few pool chemicals to prepare your water. If you live in an area where it snows or where winter temperatures get very cold, you’ll want to use chemicals and non-toxic antifreeze to prevent freezing. Even if you live in a warmer climate but still plan to close your pool, you’ll want to use the right chemicals to maintain your pool’s water chemistry.

Chemicals for winterizing your pool:

Chlorine
Algaecide
Cyanuric acid
Shock
Non-toxic anti-freeze
Depending on the pH level of your pool, which you can test on your own or collect a sample and bring it to a testing facility or local builder, you may need a pH increaser or decreaser

Note: Consult with the industry standards for pool water before using any chemicals or adjusting the pH. If you have questions, contact your local pool dealer. It’s important to check your water frequently and most dealers can test the water for you.

How to Winterize Your Pool in Cold Climates

If you live in a cold climate where temperatures drop between 25 and 50 degrees, you’ll have a few more steps in the process vs. closing a pool for more mild winters.

For cold climates, lower the water level approximately 1” beneath the skimmer and blow the water out of the pump, pipes, and any vessel that holds water to prevent damage that can occur when the water expands from freezing. Water can expand between 9-10% due to cold temperatures.

Step One

Adjust Pool pH

Adjust pool pH to 7.2-7.8. This will prevent staining, scaling and algae growth.

Step Two

Shock the Pool

Shock the pool following product directions.

Step Three

Run the Filter

Run the filter for 24-48 hours depending on how dirty the water is.

Step Four

Vacuum the Pool

Skim out floating debris and vacuum the pool thoroughly.

Step Five

Add an Algaecide

Add an algaecide to prevent algae from forming before the water has frozen.

Step Six

Lower Water Level

Follow your pool manufacturer’s directions for lowering your water level. See below for more information.

Step Seven

Drain Equipment

Turn off the filter pump and drain the pump, filter, heater, and other equipment. Store equipment to prevent damage. Follow the manufacturer’s directions for lubrication and proper covering.

Step Eight

Turn off Power

Turn off all power to the support equipment and remove fuses or turn the circuit breakers to off.

Step Nine

Remove Accessories

Remove and store accessories. If you have a slide or diving board, check with your pool professional.

Step Ten

Cover the Pool:

Cover the pool securely with a seasonal safety cover. Be sure that the edge of the cover is sealed so that wind does not get under it. A good pool cover resists water, weather, and pool chemicals and keeps out leaves and other debris.

Water Levels: How Far Down Do You Drain Your Pool for Winter?

As a general rule, you want to lower the water level to approximately 1” beneath the skimmer. You never want to drain your pool completely. If you feel there’s a need to drain your pool, contact a pool professional.

If you’re using a seasonal pool cover, be sure to follow the manufacturer’s instructions regarding the water level. Some will recommend that after blowing out the pool pipes you plug the skimmer and raise the water level to a point that it will support the cover when it’s weighed down by snow.

If you’re unsure about draining the water or any steps of the winterizing process, contact your Latham pool dealer.

How to Winterize Your Pool in Mild Climates

If you live in a mild climate, you will have a longer pool season. However, there may be periods where you use your pool very infrequently as it is not uncommon to see temperatures drop below freezing from time to time even in warmer areas. While you might not need to truly winterize your pool, you can cut back on the maintenance by following the six easy pool closing steps below.