5 Common Causes of a Smelly Spa Cover (and How to Fix Them)

Your spa's cover is an important part of the spa. It helps protect and insulate your spa, and reduce running costs.

Most quality spa covers last many years without any issues. However, if they aren't well looked after you may notice some wear and tear and occassionally, you may even notice the cover has a musty smell.

In this article, you'll learn:

• Why does my spa cover smell bad?
• How do I get the smell out of my spa cover?
• How do you prevent your spa cover from smelling bad?

Why does my spa cover smell bad?

Throughout our 25 years in the spa industry, we have received a lot of questions and inquiries from customers regarding the care of spas and swim spas. One of the more common questions our customers ask us is ‘Why does my spa cover smell musty?’.

More often than not, mould and mildew are the primary suspects when spa covers start smelling funky. Below, you will find the 5 common reasons why spa covers smell bad.

1. You have poor water chemistry.

One thing that can often be overlooked is how the quality of your spa water can affect your spa cover. The spa cover is often in close contact with your spa water, absorbing steam and heat. Bacteria and mould can easily grow in this warm, moist environment if not managed correctly. Low pH and high chlorine or ozone levels can also lead to the deterioration of the underside of your spa cover.

Aside from that, with poor sanitation and filtration, algae, bacteria, and other microorganisms can thrive in your spa, making your water unsafe. Without clean and sanitised spa water, you’re on the fast track to a smelly or musty spa cover.

2. Your spa cover is old, damaged, or broken.

The average lifespan of a spa cover is usually around 5 to 7 years. If you’ve had your spa cover for around that long, chances are your spa cover may be broken, damaged, or worn.

Worn spots, cracked foam cores, or torn seams on your spa cover can cause puddles to form on top or even inside your spa cover. This can lead to waterlogging from rain and moisture which eventually leads to mould and mildew forming inside your cover.

Check your spa cover for tears and breaks often.

3. Your spa cover is dirty on top

Aside from tears and damages, it’s important for a spa owner to be on the lookout for dirt on top of your spa cover. The top of your cover can gather leaves, dust, debris, droppings, dirt, and other materials which can contribute to a bad smell if left for too long.

4. Your spa cover is not removed regularly.

While your spa cover is meant to stay on top of your spa when your spa or swim spa is not in use, keeping it on for too long with infrequent removals is an easy way for a musty smell to form.

You may have observed the smell after a long holiday when your spa hasn’t been used.

Your cover needs to be maintained regularly to keep it in good condition - which involves taking the spa cover off the spa, giving it a thorough clean and rinsing it with fresh water, then allowing it to air out and fully dry in the sun. When it has completely dried, you can replace the cover.

You should air your cover out every few weeks if the spa is not in use.

5. Your spa cover is of poor quality.

If you purchased a cheap, low-quality spa cover, you may also experience a musty or bad smell. A high-quality spa cover is made with materials that prevent moisture from reaching the foam core, preventing waterlogging and stagnant water.

These materials include a marine-grade vinyl outer and a protective waterproof shell around the inner foam core. Cheap spa covers may be made from lesser-quality materials meaning moisture can leak into the foam. This moisture eventually becomes a breeding ground for bacteria - the culprit of the bad smells.

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How do I get the smell out of my spa cover?

You finally know why your spa cover smells bad. Now, what do you do with it?

Follow these steps to get rid of the bad smell from your spa cover.

• Remove the spa cover. Take the spa cover off of the spa and place it somewhere it will not be disturbed. Pro-tip: be sure to keep it away from pets and children, preferably somewhere sunny or with low humidity.
• Clean and disinfect. Depending on the state of your spa cover, you may need to pull out the big guns for this. Make sure to be as gentle as possible when cleaning, and use products specifically made for spa covers. Do not use household cleaning products as they may end up in your spa water.

We recommend the following products from the Spa Store:

If you want tips on how to look after your spa cover, check out the article below.

• Allow the panels to dry. After cleaning, make sure to give your spa cover time to dry out completely before putting it back on your spa cover. This will ensure that none of the cleaning products will end up in your spa water.
• Check for breaks, tears, and other damages. While your spa cover dries, use this time to take inventory of the state of your spa cover. Make sure to patch holes as you see them.
• Buy a replacement if necessary. If your spa covers foam core is compromised or waterlogged, no amount of patching will save it. In this case, you’re better off buying a new spa cover instead.

How do you prevent your spa cover from smelling bad?

If it happened once, it could happen again! We’re sure you do not want a repeat experience, so how do you stop this from happening again?

Here are our top 3 tips to prevent bad smells from your spa cover.

Sanitise and balance your spa water.

Good chemistry in your water goes a long way in ensuring that your spa cover smells just as it should–and by that we mean good. Use the right spa chemicals and follow the chemical instructions to make sure that your spa is properly clean and sanitised at all times.

Need to learn how to sanitise and balance your water? Below is a complete guide to help you with water care and maintenance.

Maintain a regular cleaning schedule.

Just as you should keep a regular maintenance schedule for your spa pool or swim spa, you should also maintain a regular cleaning schedule for your spa cover.

Make sure to wipe it down at least once a week and apply UV protectant every 3 to 5 weeks.

For a complete guide on how to care for your spa cover, check out the link below.

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Is it time to replace your spa cover?

Sometimes, the only way to permanently solve the problem of a smelly spa cover is to get rid of the spa cover. A waterlogged spa cover is impossible to clean, so you’re better off buying a new one. Make sure to buy one with the following characteristics:

• U.V. resistant marine grade vinyl outer
• Rugged U.V. resistant stitching
• Chlorine resistant p.e. plastic on the underside to eliminate bleaching
• High strength polystyrene foam sheets sealed in heavy-duty heat sealed plastic to stop water logging.
• Internal foam centre reinforced with an aluminium channel for added strength.
• 90mm to 60mm internal foam core taper to prevent surface ponding
• Reinforced central hinge for years of service
• Heat lock hinge block the full length of the hinge to stop heat loss at hinge
• Internally reinforced handles
• Reinforced adjustable tie downs
• New locking latches and buckles

Is it time for your spa cover to be replaced?

We would be happy to suggest a replacement spa cover or hot tub cover that is the right fit for your spa. Complete the form below and we will get back to you with pricing and an ETA for the spa cover that best fits your spa.

Need help measuring your spa cover? Check out the guide below.

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In Summary

A smelly spa cover is usually caused by mould and mildew build-up which can be caused by a few things such as:

• Old, damaged, or broken spa cover
• Dirty spa cover
• Infrequent removal
• Poor-quality spa cover
• Poor water chemistry
• The best way to get rid of the bad smell from your spa cover is by removing the cover and thoroughly cleaning it. You can prevent future occurrences by keeping your water sanitised and balanced as well as maintaining a regular cleaning schedule.

However, if the spa cover is waterlogged, too heavy, and has too much damage, the best course of action is usually to replace it.

Got more questions?

Talk to us on live chat, or email us your spa questions and we'll be happy to help!