Hot tubs are perfect for unwinding after a long day, but they require regular maintenance to keep them in pristine condition. One of the most common issues hot tub owners face is scale—those unsightly, chalky white deposits that form on the surfaces and components.
Not only does scale detract from your hot tub’s appearance, but it can also interfere with its functionality by clogging the jets, reducing water flow, and putting strain on the heating elements.
Fortunately, removing scale from a hot tub isn’t as difficult as it may seem. With the right tools, cleaning products, and maintenance practices, you can remove scale from hot tub and ensure it stays in great working condition for years to come.
What is Scale and Why Does it Form in Hot Tubs?
Scale, also known as calcium build-up, is a type of mineral deposit that forms in hot tubs, primarily due to an excess of calcium and magnesium in the water. These minerals are naturally present in varying concentrations in tap water, especially in areas where “hard water” is common.
When the water in your hot tub is imbalanced—meaning the pH, alkalinity, or calcium hardness levels are too high—the minerals begin to separate from the water and cling to surfaces. Over time, this creates hard, stubborn deposits, particularly around the waterline, inside the jets, and along the heater.
Common causes of scale include:
- Hard Water: If your water supply is hard (high in calcium and magnesium), your hot tub is more susceptible to scale formation.
- High pH Levels: Water with a pH above 7.8 tends to promote the precipitation of calcium carbonate, which leads to scale.
- High Alkalinity: Water that has a high total alkalinity level will struggle to maintain a proper pH balance, increasing the likelihood of scale formation.
- Temperature Fluctuations: Hot tubs that regularly experience rapid temperature changes can contribute to scale buildup, as calcium and magnesium settle out of the water more quickly when heated.
Understanding why scale forms is key to removing and preventing them from returning.
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Step-by-Step Guide to Remove Scale from Hot Tub
To remove scale from your hot tub, drain the water, scrub surfaces with a vinegar-water solution or a descaling cleaner, and clean out filters and jets. After refilling, maintain proper water chemistry and use a scale inhibitor to prevent future deposits.
Follow these steps to get rid of the existing scale and restore your hot tub to its original, smooth finish.
Step 1: Drain the Hot Tub
Removing the scale is much easier when your hot tub is empty. Draining the water allows you to clean every part of the tub thoroughly without worrying about spreading debris throughout the system.
- Turn off the power: Safety is key, so make sure the hot tub is switched off and unplugged before draining.
- Locate the drain valve: Most hot tubs come with a built-in drain valve or plug. Attach a garden hose to the valve to direct the water away from the hot tub, preventing any flooding around your yard or patio.
- Use a submersible pump for speed: If you want to speed up the draining process, a submersible pump can significantly reduce the time it takes to empty your tub.
Pro Tip: While the hot tub is empty, take the opportunity to clean the tub’s cabinet and other exposed parts. Regular maintenance extends the life of your hot tub and helps it look new.
Step 2: Scrub the Surfaces
Once the tub is drained, you’ll have a clear view of where the scale has built up. The key here is using the right cleaning products to safely remove scale without damaging the hot tub shell.
- White vinegar and water solution: For light to moderate build-up, mix equal parts white vinegar and water in a spray bottle. Vinegar’s acidity works to break down mineral deposits gently. Spray it generously on the affected areas and let it sit for 10–15 minutes before scrubbing with a soft sponge or brush.
- Commercial descaling products: If the scale build-up is particularly stubborn, a specialized descaling cleaner can do the job more effectively. These cleaners are specifically designed to dissolve calcium deposits quickly without harming the acrylic or vinyl shell of your hot tub. Apply the cleaner according to the instructions and scrub the areas thoroughly.
- Avoid harsh abrasives: Stick to non-abrasive cleaning tools such as soft sponges or nylon brushes to avoid scratching your hot tub’s surface. Abrasive materials can damage the tub’s finish and make it more prone to future scale build-up.
Step 3: Clean the Filters and Jets
Scale doesn’t just form on the surface—it can also clog up your filters and jets. This affects water flow, making your hot tub less efficient and reducing the overall spa experience.
- Soak the filters: Remove the filters from the hot tub and soak them in a filter cleaner or a diluted vinegar solution (use a 4:1 ratio of water to vinegar). Soak for several hours to dissolve mineral build-up inside the filters, then rinse them thoroughly before re-installing.
- Clean the jets: Using a small brush or pipe cleaner, carefully clean the jets. Be thorough, as mineral deposits can obstruct water flow and lead to equipment strain. If your jets are removable, take them out for a more detailed cleaning.
Pro Tip: Consider running a jet cleaner through the system before draining the hot tub. This helps to dislodge any internal build-up and makes the final cleaning process much easier.
Step 4: Refill and Balance the Water
After you’ve thoroughly cleaned the hot tub, it’s time to refill it with fresh water.
- Use a pre-filter: If you live in an area with hard water, using a hose pre-filter can significantly reduce the mineral content in the water before it enters your hot tub. This is an easy way to prevent scale from forming again too soon.
- Balance the water chemistry: As you refill the tub, test the water chemistry and adjust it to the recommended levels:
- pH: Keep the pH between 7.2 and 7.8 to avoid mineral precipitation.
- Alkalinity: Maintain alkalinity levels between 80 and 120 ppm to help stabilize pH.
- Calcium hardness: Aim for calcium levels between 150 and 250 ppm. Too much calcium leads to scale; too little can cause corrosion.
Regular testing is essential to keeping your water balanced and preventing future scale.
Step 5: Add a Scale Inhibitor
A scale inhibitor (a sequestering agent) is a great preventative measure to stop minerals from precipitating and forming deposits. These products bind with calcium and other minerals in the water, keeping them in suspension rather than allowing them to stick to surfaces.
- Follow product instructions: Each scale inhibitor is different, so read the manufacturer’s instructions to determine how much to use based on the size of your hot tub. Adding this to your regular maintenance routine can dramatically reduce the chance of future build-up.
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Tips for Preventing Scale Build-Up in Hot Tub
While cleaning scale from your hot tub is important, prevention is the ultimate solution. By taking some proactive steps, you can minimize the occurrence of scale and avoid the hassle of cleaning it later.
- Regularly check water chemistry: Test the water at least once a week to ensure the pH, alkalinity, and calcium hardness levels are in the correct range. Balancing your water chemistry is the most effective way to prevent scale.
- Drain and clean quarterly: It’s a good idea to drain and thoroughly clean your hot tub every 3–4 months, even if you haven’t noticed scale build-up. This helps to flush out any minerals that may be starting to settle.
- Use a scale inhibitor consistently: Add a scale inhibitor to your water every time you refill the tub. These products offer long-term protection against mineral deposits and are a simple way to keep scale in check.
- Address water hardness: If you live in a region with particularly hard water, using a water softener or pre-filter can make a significant difference in the longevity of your hot tub.
End Note
Scale is a common issue for hot tub owners, but it doesn’t have to be a permanent problem. By following these simple steps to remove existing build-up and taking preventative measures, you can keep your hot tub scale-free and running smoothly. Regular maintenance and attention to water chemistry are the best ways to protect your investment and ensure your hot tub remains a relaxing retreat for years to come.
By staying on top of cleaning and water care, you can avoid the headache of future scale issues—and get back to what matters most: enjoying your time in the hot tub!
