Pool Blanket in Winter (Perth): When to Use It, When to Take It Off, and What It Does to Your Chlorine

Should You Use a Pool Blanket During Winter?

Absolutely.

A quality pool blanket (also called a solar cover) helps reduce evaporation, keeps leaves and debris out, retains valuable heat, and can even lower your running costs by reducing the workload on your heating system. However, winter pool care in Perth is different from summer. Cooler water temperatures, shorter daylight hours, and reduced pool use all change the way your pool chemistry behaves. At Crystal Clear Pool Care, one of the most common winter issues we see isn't algae, it's perfectly healthy pools that become dull, cloudy, or over-chlorinated simply because the blanket stays on for weeks at a time.

The good news? A few small adjustments can prevent most of these problems.

Why Winter Changes Everything

During a Perth winter:

• Water temperatures drop.

• Pools are used far less.

• UV levels are much lower than in summer.

• Chlorine demand naturally decreases.

That means your pool simply doesn't need as much chlorine as it does during the warmer months. If your chlorinator is still running on summer settings while the blanket remains on most of the time, chlorine can gradually accumulate faster than it's being consumed. This is particularly common with saltwater pools.

How a Pool Blanket Affects Chlorine

Think of your pool blanket as placing a lid on your swimming pool. While that's excellent for keeping heat in, it also reduces the natural processes that help maintain balanced water chemistry.

With the blanket on for extended periods:

• Less sunlight reaches the water.

• UV light destroys less free chlorine.

• Water exchanges less with the surrounding air.

• Chlorine remains active for longer.

• Chlorine production can exceed demand.

The result can be chlorine levels that slowly climb without you noticing. Many pool owners don't realise there's a problem until they remove the blanket and are greeted with that unmistakable strong chlorine smell.

Signs Your Blanket Is Trapping Too Much Chlorine

You may notice:

• A strong chlorine smell when lifting the cover

• Burning eyes after swimming

• Skin irritation

• Faded pool blankets or surrounding surfaces over time

• Water that appears dull or slightly milky despite testing as sanitised

• Higher-than-normal chlorine readings

Interestingly, a strong chlorine smell doesn't always mean there's "too much chlorine." It can also indicate imbalanced water chemistry or chloramines, which is why regular water testing is important.

Why Cloudy Water Happens in Winter

Cloudy water is rarely caused by a single issue. More often, it's the result of several small problems occurring together.

A typical scenario looks like this:

1. The blanket stays on continuously.

2. Pump run times are reduced to save electricity.

3. Skimmer baskets slowly fill with leaves.

4. The filter becomes dirty.

5. Water circulation decreases.

6. Fine particles aren't removed efficiently.

7. The pool begins looking cloudy or dull.

Because the changes happen gradually, many homeowners don't notice until spring arrives.

When Should You Leave the Blanket On?

For most Perth pools, leave the blanket on whenever you're trying to:

• Reduce evaporation

• Keep leaves and debris out

• Retain warmth overnight

• Improve heating efficiency

• Reduce chemical consumption

If your backyard is surrounded by trees, a blanket can significantly reduce cleaning time throughout winter.

When Should You Take the Blanket Off?

This is the step many pool owners skip. Even during winter, your pool benefits from being uncovered regularly. We generally recommend removing the blanket for around 30–60 minutes several times each week, particularly on mild sunny days.

Doing this allows:

• Fresh air to circulate

• Water gases to escape

• Chlorine levels to stabilise naturally

• A quick visual inspection of your pool

• Debris to be removed before it sinks

If you notice a strong chlorine smell when lifting the blanket, leave it off for longer and perform a water test before replacing it.

Winter Chlorinator Settings

Every pool is different, so there's no single percentage that suits everyone.

Your ideal setting depends on factors such as:

• Pool size

• Water temperature

• Pump run time

• Recent weather

• Swimmer load

• Water test results

As a general rule, many Perth salt pools require significantly lower chlorinator output during winter than they do in summer. Rather than choosing a fixed percentage, adjust your chlorinator based on accurate water testing. If you're unsure, a professional water balance can usually dial it in within one visit.

Simple Winter Checklist

Once each week, spend just a few minutes checking the basics:

✅ Test chlorine and pH

✅ Empty skimmer and pump baskets

✅ Check the water level

✅ Ensure the pump is circulating properly

✅ Clean or backwash the filter if required

✅ Lift the blanket for fresh air circulation

These simple habits prevent many of the problems that lead to expensive repairs or green pool recoveries later.

When Should You Call a Professional?

If you're experiencing any of the following, it's worth having your pool professionally assessed:

• Cloudy water that won't clear

• Consistently high chlorine readings

• Strong chlorine smell beneath the blanket

• Unsure how to adjust your chlorinator

• Poor circulation

• Dirty or ageing filter

• Unsure whether your pump is running long enough

Winter is the ideal time to correct small issues before they become major problems during spring.

Looking After Your Pool Blanket

Your blanket itself also benefits from a little maintenance.

To maximise its lifespan:

• Hose it off occasionally to remove dirt and debris.

• Avoid dragging it across rough paving.

• Store it on a roller whenever possible.

• Keep chlorine levels within the recommended range.

• Replace damaged or brittle blankets before they begin falling apart.

A well-maintained blanket can last for many years and continue saving water, chemicals, and heating costs.

Need Help Getting Your Pool Winter-Ready?

Crystal Clear Pool Care provides professional pool servicing throughout Perth CBD and southern suburbs, helping homeowners keep their pools clean, balanced, and ready to enjoy all year round. Every service includes professional digital water testing, equipment inspections, and a detailed electronic service report explaining exactly what was checked and any recommendations for your pool. Whether you need your chlorinator adjusted, your filter serviced, or simply want confidence that everything is operating correctly, we're here to help.

Book your winter pool service today and enjoy crystal clear water all season long.