When Should I Winterize My Pool and How Do I Avoid Expensive Repairs?

What really happens if you don’t winterize your pool the right way? And can you actually save money doing it yourself – without wrecking your pool and pool equipment. In this article, we will share step-by-step processes to help you protect your pool from freezing damage, avoid green swamp water in spring and save hundreds in possible repair cost.

Yes, hiring a professional to winterize your pool can cost between $150-$400 for labor and materials, while doing it yourself could save you $75-$200. Here's what most pool owners don't realize: skipping proper winterization is like rolling the dice with thousands of dollars. Water expands when it freezes, and that expansion can crack pipes, damage pumps, and destroy equipment. We're talking about lowering water levels 4-6 inches below the skimmer inlet or tile line, balancing your water chemistry, and protecting your plumbing system from freezing.

The good news, pool winterization doesn't have to feel overwhelming. Sure, professionals offer convenience, but plenty of pool owners handle this seasonal task themselves. You've got options too – you can either blow out the lines with compressed air and seal them or partially drain the pool and add anti-freeze to the lines. 

Getting your timing right can mean the difference between a smooth spring opening and thousands in repair bills. After years of helping Arizona pool owners protect their investments, I can tell you that starting at precisely the right moment prevents both algae nightmares and expensive freeze damage.

Ideal temperature to begin

Once your pool water consistently stays below 65°F, it’s time. That’s because algae stops growing, and your chemicals last longer. Wait too long, and freezing water could break your pipes. Start too early, and algae will grow all winter.

Here's why 65°F matters: algae growth slows dramatically, allowing your winter chemicals to stay effective throughout the off-season. Your sanitizers also stick around longer at this temperature, keeping your pool algae-free during the dormant months.

Most pool owners mess this up by closing too early or waiting too long. Monitor both air and water temperatures starting in late summer through early fall. Some experts even suggest waiting until water temperatures hit 50°F for the best results.

For those of us in the Phoenix Valley, this timing usually falls in late fall. Our mild desert climate lets us stretch the swimming season compared to colder regions – but don't let that fool you into thinking timing doesn't matter.

Signs it's time to start winterizing:

• Daytime temperatures consistently stay below 65°F
• You've stopped using the pool regularly
• Weather forecasts show a cooling trend
• Nighttime temperatures are dropping significantly

Get your timing wrong, and you'll face problems from two directions. Close too early while temperatures still exceed 65°F, and you're asking for trouble. Warmer water burns through sanitizing chemicals faster, creating perfect breeding conditions for algae. Come spring, you'll be staring at a green, murky mess that requires intensive cleaning and extra chemical treatments.

Wait too long? That brings its own set of expensive headaches. Water expands 9-10% when it freezes, creating enough pressure to cause serious damage to your pool equipment and plumbing. This expansion can crack plastic, split metal, or destroy anything holding water.

The most expensive pool repairs I see come from freeze damage to pipes, pumps, filters, and other equipment. We're talking thousands of dollars in repairs – all preventable with proper timing.

Your winterization chemicals also work better when you time things right. Close the pool when it's cool enough that the chemicals will last until spring. This sweet spot means you won't face a lengthy, costly opening process next season.

Even here in Arizona's mild climate, you need to protect equipment from those occasional freezing temperatures. The Phoenix Valley might not see harsh winters, but unexpected cold snaps can damage unprotected pool systems. Pay attention to weather forecasts as winter approaches – your specific location might have its own microclimate considerations.

Start your pool winterization at the right temperature, and you'll protect your investment throughout winter while setting yourself up for an easier, less expensive opening next spring.

The right winterization sequence makes all the difference between a pool that survives winter and one that costs you thousands in repairs. Here's exactly how to protect your investment, step by step.

1. Clean and vacuum the pool

Here's something most pool owners get wrong: they rush straight to chemicals without properly cleaning first. Don't make that mistake.

Start by brushing every wall and floor surface to eliminate algae and dirt. Think of it like putting away toys with mud still on them — everything gets messier later. If you leave dirt or algae in the water now, it’ll turn your pool green by spring.

Skim the surface to remove leaves, debris, and insects. Then vacuum the entire pool floor thoroughly. The cleaner your pool at closing, the cleaner it will be when you reopen in spring. It's that simple.

Got excessive algae? Vacuum to waste by bypassing the filter and sending waste out the backwash line. This prevents your filter from clogging constantly during the cleaning process.

2. Balance water chemistry

Water chemistry acts as your first line of defense against winter problems. Get these numbers right, or you'll pay for it later:

• pH: 7.2 to 7.6 pH helps keep the water from becoming too acidic (which can damage parts) or too basic (which can lead to cloudy water).
• Total Alkalinity: 80 to 120 ppm Alkalinity helps keep the pH stable
• Calcium Hardness: 200 to 400 ppm Calcium hardness will protect your pool surface from cracking or scaling.
• Chlorine: 1 to 3 ppm

But here's what the pros do differently: they raise alkalinity to between 150 and 175 ppm and pH to 7.8 before winter hits. Why? Because these levels naturally decrease in stagnant water over winter. You're planning ahead.

3. Add winterizing chemicals

Several days before closing, shock your pool to kill existing algae and bacteria. Look for products with at least 65% sodium hypochlorite or equivalent non-chlorine alternatives.

Wait for chlorine levels to drop back to 1-3 ppm, then add winter algaecide. This prevents algae growth during those long dormant months. Many pool owners also add enzyme treatments to break down oils and sunscreen residue – smart move if you've had heavy pool use.

Hard water area? Calcium hardness over 400 ppm? Add a scale preventative like Natural Chemistry's Scale Free.

4. Lower the water level

The water level you choose depends entirely on your cover type:

• Mesh safety covers: Lower water 12-18 inches below the skimmer
• Solid floating covers: Lower water 3-6 inches below the skimmer
• Using skimmer plugs: You may not need to lower the water at all

Never completely drain your pool. The ground pressure can actually damage your pool structure. Use your filter pump (if you have a main drain) or a submersible pump to hit the right level.

5. Remove and store pool accessories

Every ladder, handrail, skimmer basket, cleaner, float, and toy needs to come out and get stored properly. This extends their lifespan and ensures they're ready next season.

Clean each item with mild soap and water. Make sure everything's completely dry before storage to prevent mildew. Store in a dry, protected space away from freezing temperatures.

For inflatable items, deflate completely and store in sealed containers. This protects them from both cold and pests.

6. Cover the pool securely

Your cover choice affects everything else. Two main options:

Safety covers provide the best debris protection and prevent accidental falls. They must be anchored securely to work properly.
Winter covers offer less protection but don't require the extra anchoring step.

Check that your cover fits tightly without holes or tears. Solid covers need a cover pump to remove rainwater and snow melt.
For Phoenix Valley residents, Shasta Pools Supply carries quality pool covers and winterization supplies designed for Arizona's unique climate needs.

Here's the truth about freeze damage: it's the number one cause of expensive pool repairs. We're talking about cracked pipes, destroyed pumps, and repair bills that can easily hit thousands of dollars. The worst part? It's completely preventable.

Turn off and drain pump and filter

First things first - shut off power to everything. Turn off the gas supply to your heater and the gas valve itself. Switch off the breaker to your pump and automation system. If you've got actuators, position them correctly so pool water can't drain back.

Once everything's powered down, close any valves between your equipment and pool that could cause draining. Now comes the critical part: remove drain plugs from your pump, filter, and heater to allow complete water drainage.

Got cartridge filters? Remove the filter element, clean it thoroughly, and let it dry completely. Store those cartridges indoors during winter - trust me on this one.

Sand filter owners, here's your sequence: backwash for at least 30 minutes before closing, remove the drain cap at the bottom, and set the control valve between RINSE and FILTER. Don't forget to unscrew and store pressure gauges indoors.

Blow out return and suction lines

Frozen pipes are every pool owner's nightmare. When water freezes, it expands with enough force to crack your plumbing lines. Here's how to prevent that disaster:

• Connect an air compressor or shop vac to the skimmer or dedicated blower port
• Blow air through each skimmer until only air (no water) emerges
• Watch for a steady stream of bubbles in the pool
• Move to the return lines next, plugging each one after clearing
• Blow out the main drain for 20-30 seconds after seeing air plumes

Keep going until the blower's sound changes - that tells you all water has been expelled. Critical tip: keep blowing while closing valves to maintain air pressure in the lines.

Use antifreeze in skimmer and pipes

After blowing out the pipelines, add pool-specific antifreeze for extra protection. Never use automotive antifreeze - it's toxic. The rule of thumb? One gallon of pool antifreeze for every 10 feet of 1.5-inch pipe.

For skimmer protection:

• Pour antifreeze directly into the skimmer after plugging it
• Use a Gizzmo or skimmer guard to protect against ice expansion
• Consider placing a partially-filled antifreeze jug in the skimmer to absorb expansion

Store drain plugs and small parts safely

You know what's frustrating? Losing those tiny drain plugs and spending spring searching for replacements. Keep track of all removed drain plugs, skimmer baskets, return jets, and other small components. Store these items together in a labeled container. Many pool owners use zipper storage bags to keep everything organized.

For Arizona pool owners in the Phoenix Valley area, Shasta Pools Supply offers specialized winterization kits containing all the plugs, antifreeze, and supplies you need for proper equipment protection.

Saltwater pools aren't just "set it and forget it" when winter arrives. These systems need extra attention, and skipping these specific steps could cost you big when it comes to replacing expensive salt system components.

Check and adjust salinity

Here's something that catches many saltwater pool owners off guard: your salt system might start screaming "low salt" as temperatures drop, but don't rush to add more salt just yet. Water conductivity decreases as temperatures drop, causing salt systems to display inaccurate low salt readings.

Instead, grab some salt test strips or a digital salinity tester for accurate measurements. Keep salt levels at the lower end of the manufacturer's recommended range to prevent unsightly staining. Whatever you do, don't add extra salt in the weeks before closing since salt can react with contaminants in colder water.

Clean and store the salt cell

Your salt system knows when to quit - most automatically deactivate below 50-60°F. But that doesn't mean you can leave the cell in place. Removing the cell is essential to prevent freeze damage.

First things first: turn off all power to pool equipment. Then disconnect the cell by unscrewing the unions. Now comes the cleaning part - use a high-pressure hose or wooden tool (never metal) to remove scale buildup. Got stubborn deposits? Soak the cell in diluted muriatic acid following manufacturer instructions. Once it's clean and completely dry, store it indoors until spring.

Winterize salt system components
Consider installing a "dummy cell" to maintain proper spacing in your plumbing. Think of it as a placeholder that keeps your lines sealed throughout winter. Your power supply can usually stay mounted outdoors (most manufacturers design them for this), but bringing it inside extends its lifespan.
Don't forget the basics either - properly blowing out and plugging all return and suction lines remains just as important for saltwater systems.

At Shasta Pool Supply in Phoenix Valley, we stock specialized winterization kits designed specifically for saltwater pools.

Let's talk money. Pool winterization costs vary wildly and understanding exactly what you're looking at helps you make the right call for your situation and budget.

Think of it like this:

• DIY Supplies: $40–$100
• Pro Service: $175–$300
• Repairing Freeze Damage: $350–$5,800.

Winterizing your pool properly is one of those tasks that separates smart pool owners from those facing expensive spring surprises. You now have the knowledge to protect your investment from freeze damage, whether you tackle it yourself or hire professionals.

The choice between DIY and professional service really comes down to your comfort level with pool maintenance. Professional services cost more upfront, but they bring expertise that prevents costly mistakes. Handle it yourself, and you'll save money while staying in complete control of your pool's care.

Your equipment needs special attention during winterization. Drain those pumps, blow out the lines, and protect your skimmers properly. These steps prevent the freeze damage that causes most winter-related pool repairs. Saltwater pool owners, don't forget those extra steps like removing and storing your salt cell.

At Shasta Pools Supply, we've been helping Phoenix Valley pool owners winterize successfully since 1966. Our family-owned business stocks all the chemicals, covers, antifreeze, and specialized equipment you need. Whether you're going DIY or professional, we've got everything to protect your pool through Arizona's mild but occasionally freezing winters.

The bottom line, take the time to winterize correctly now, and you'll face less work, fewer expenses, and more fun when swimming season returns. Your pool represents a serious investment in your home and lifestyle. Protect it properly this winter, and you'll enjoy many more seasons of trouble-free swimming ahead.

10 Essential Steps to Closing Your Pool - https://hayward.com/blog/post/ten-essential-steps-to-closing-your-pool

How Do I Winterize My Pool Equipment? - https://www.raypak.com/how-do-i-winterize-my-pool-equipment/