designer pool covers A blue house with a pool in the backyard.

Does a pool cover increase chlorine?

Many pool owners wonder if using a pool cover affects the amount of chlorine needed. Interestingly, a covered pool uses less chlorine because it’s shielded from UV light, which breaks down chlorine.

This blog will explore how pool covers contribute to maintaining your swimming pool’s water chemistry and save you money on chemicals in the long run. Keep reading to find out more!

Key Takeaways

  • Using a pool cover stops UV light from making chlorine vanish quickly. This means you use less chlorine, saving money and effort.
  • Too much chlorine can harm your pool cover, causing it to age faster and lose its colour.
  • Pool covers trap heat in the water, so you may spend more keeping the pool warm but save on reheating costs.
  • Choosing a durable pool cover that can handle sun exposure is smart. It lasts longer and works better.
  • Remember to look after your pool cover properly to make sure it keeps helping your pool for many years.

Understanding Chlorine’s Role in Swimming Pools

A pool maintenance worker adding chlorine to a clear blue swimming pool.
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Chlorine is the superhero of swimming pool maintenance, jumping into action to fight off germs and bacteria. It forms hypochlorous acid in the water – a powerful force that kills harmful microorganisms.

This keeps swimmers safe from waterborne illnesses that could spoil the fun.

Adding chlorine to pools also deals with another unseen foe: organic contaminants. These are bits that wash off people when they swim – like sweat or lotions. Chlorine attacks these invaders, stopping the water from turning cloudy.

It helps keep pool water crystal clear, so you can see all the way to the bottom. The right chlorine concentration is key; it boosts ORP levels which mean better sanitising power and safer swims for everyone.

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The Impact of Pool Covers on Chlorine Levels

A clean pool covered with a protective cover in a well-maintained garden.
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Pool covers shield pool water from UV light, reducing chlorine breakdown. They also minimise chlorine evaporation, helping to maintain adequate levels for water sanitation.

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The effect of UV light on chlorine

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Covering your pool helps fight against UV damage. It stops those harmful rays from reaching the water and eating away at the chlorine. With a cover on, your pool doesn’t lose as much chlorine, which means it stays cleaner with less effort and expense.

Chlorine evaporation and pool covers

Pool covers play a crucial role in maintaining chlorine stability in swimming pools. They block UV light, which is known to break down chlorine rapidly. This protection helps to preserve the sanitiser levels needed to keep the water clean and safe for swimmers.

With a cover on, less chlorine evaporates into the air, meaning you won’t have to add it as often.

Moreover, these covers are effective at preventing evaporation—not just of water but also of precious chlorine. By keeping the pool covered when not in use, chlorine gets a chance to recirculate through the water instead of disappearing into thin air.

This cycle ensures that sanitiser levels remain consistent, supporting overall water chemistry and reducing the need for frequent maintenance or additional chemicals.

How High Chlorine Levels Affect Pool Covers

High chlorine levels can cause premature aging and discoloration of pool covers. Corrosive effects on pool covers are also observed with high chlorine concentrations.

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Premature aging and discoloration

Chlorine doesn’t just keep your pool water clean; it has a side effect on pool covers. Over time, too much chlorine leads to the cover suffering from premature aging and discoloration.

The vinyl liners can turn bleached and faded, losing their vibrant colours. This isn’t merely about looks—its integrity gets compromised as well.

Cementitious finishes aren’t spared either. They might show signs of calcite crystals forming, along with noticeable discolorations that weren’t there before. It’s all due to a major pH spike driven by high chlorine levels in the water touching these surfaces day in and day out.

Continuous chemical exposure speeds up the wear and tear process considerably, making frequent replacements a harsh reality for many pool owners.

Corrosive effects on pool covers

High chlorine levels pack a punch against pool covers, speeding up their aging process. This often leads to the covers becoming bleached and discoloured. Think of it as the cover losing its vibrant colours and strength much faster than expected.

The chemistry behind this is quite straightforward – more chlorine means a more acidic environment for your pool cover, which doesn’t bode well for its longevity.

Pool covers facing such harsh conditions can start showing signs of corrosion early on. Once the damage kicks in from elevated chlorine levels, there’s no turning back; those effects are irreversible.

Pool maintenance becomes crucial here, balancing chemical treatments to prevent acidic conditions that fuel cover degradation. It’s not just about keeping water clean but also ensuring your pool cover stays in top-notch condition for years to come.

The Pros and Cons of Using Pool Covers

Pool covers reduce chlorine consumption, leading to cost savings and less frequent chemical adjustments. On the other hand, pool covers can increase heat retention, potentially causing higher energy costs for maintaining comfortable water temperatures.

Reduced chlorine consumption

A pool cover acts like a shield, blocking UV rays from reaching the water. This is crucial because UV light has a knack for breaking down chlorine. With less UV exposure, your pool doesn’t lose chlorine as fast.

It means you won’t have to add more of it too often. Less chlorine used equals savings in maintenance costs and time.

Using a pool cover goes beyond just keeping leaves out; it’s about conserving what keeps your pool clean – chlorine. The sun can cut down on your pool’s chlorine by up to 60%. But with a cover, this drastic reduction slows down.

You’ll find yourself using fewer chemicals, making for not only an eco-friendlier option but also lighter on your pocket over time.

Increased heat retention

Using a pool cover dramatically cuts back on the need to constantly reheat your pool. It can ramp up heat retention by as much as 75%. This makes for a cosy swim any time of day and slashes heating costs significantly.

Think of it like wrapping your swimming area in a snug, energy-efficient blanket.

Pool covers not only keep the warmth locked in but also ensure the water stays at a comfortable temperature longer. Even when no one’s taking a dip, these thermal barriers prevent precious heat from vanishing into thin air.

They’re your secret weapon against chilly nights and cooler days, turning your pool into a temperatureregulating oasis.

Choosing the Longest Lasting Pool Cover

Quality pool covers are essential for ensuring durability and maximum lifespan. When selecting a cover, prioritise high-quality materials that can withstand UV exposure and offer extended longevity.

Regular maintenance and correct care significantly impact the lifespan of the cover, making it crucial to invest in a durable option. Bubble covers have a limited lifespan, lasting only around 50 – 125% depending on proper cover care.

For lifespans of pool covers to reach their maximum potential, understanding the importance of quality materials and diligent maintenance is paramount. Quality matters when it comes to choosing a long-lasting pool cover – investing wisely will pay off in prolonged durability and effectiveness.


In conclusion, pool covers can effectively reduce the need for chlorine in swimming pools. They shield the water from UV light, slowing down chlorine degradation and evaporation, thus lowering chemical usage.

By preventing algae growth and heat loss, pool covers contribute to better water quality and decreased reliance on additional chlorine. It’s essential to select a suitable cover type that aligns with your specific needs to maximise benefits and maintain proper water chemistry.

Regular monitoring is crucial to ensure optimal functionality of pool covers for long-lasting effectiveness in managing chlorine levels.

For more information on selecting a durable option that suits your needs, please visit our guide to the longest lasting pool covers.


1. Will using a pool cover increase chlorine levels?

Using a pool cover can help retain chlorine in the water by preventing evaporation, thus potentially increasing chlorine levels.

2. What type of pool covers can help maintain chlorine levels?

Both solar and insulated covers are effective in reducing chlorine loss by blocking sunlight and minimising evaporation.

3. Do I still need to monitor and adjust chlorine levels if I use a pool cover?

Yes, regular monitoring is essential as other factors like weather conditions and usage can affect chlorine levels despite using a cover.

4. Can a pool cover completely eliminate the need for adding more chlorine?

While it reduces the frequency of adding more chlorine, occasional adjustments may still be necessary due to various environmental factors.

5. How should I care for my pool cover to ensure it maintains optimal performance in retaining chlorine?

Regular cleaning and proper storage when not in use will help extend the life and effectiveness of your pool cover in preserving chlorine levels.