How to Remove Scale From Hot Tub

How to Remove Scale From Hot Tub?

Have you ever noticed a white, crusty residue lining the walls of your hot tub? That’s the hot tub scale.

A hot tub scale is a hard, white deposit that can build up on the surfaces of your hot tub, including the walls, jets, and plumbing. It can be unsightly and can also make your hot tub less efficient. So,

How to Remove Scale From Hot Tub?

To remove scale use:

  • White vinegar: White vinegar is a mild acid that can help to dissolve scale. Add 2 cups of white vinegar to your hot tub and run it for 2 hours. Be sure to rinse your hot tub thoroughly afterward.
  • Citric acid: Citric acid is another mild acid that can be used to remove scale. Add 1/2 cup of citric acid to your hot tub and run it for 2 hours. Be sure to rinse your hot tub thoroughly afterward.
  • Commercial scale remover: There are also several commercial-scale removers available. Follow the instructions on the product label.
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Here’s a simple water hardness table that categorizes the levels of hardness commonly found in water:

WordPress Tables Plugin

This table provides a quick reference for determining the hardness level of your water. Soft water has fewer minerals, whereas very hard water is high in mineral content. Understanding your water’s hardness can help you better manage and prevent scale buildup in your hot tub.

Unveiling the Mystery of Hot Tub Scale – What Are They and the Causes Behind

The hot tub scale is primarily made up of calcium carbonate, a substance left behind when hard water evaporates. You might think of it as the hot tub’s way of telling you it’s not happy with the water quality. When your water has high levels of calcium or other minerals, these can crystallize out and form scale on the surfaces of your hot tub.

So, what causes this unwelcome phenomenon? It’s not just about the water you pour in; it’s also about how you treat it. Here are some culprits:

  1. Hard Water: If your home’s water supply has high mineral content, these minerals can concentrate over time in your hot tub, leading to scale.
  2. Highly Alkaline Water: Water with high pH levels can encourage the formation of scale. Keeping the pH balanced is crucial in preventing scale buildup.
  3. Heat: Hot tubs are, well, hot. Heat speeds up the evaporation process, leaving minerals behind to form scale.
  4. Evaporation: As water evaporates, it becomes more concentrated with minerals, which then cling to the sides as scale.
  5. Chemical Imbalance: Improperly balanced hot tub chemicals can lead to a variety of issues, including scale.
  6. Stagnant Water: Water that doesn’t circulate well tends to deposit minerals in certain spots, resulting in scale.
  7. Body Oils and Contaminants: These can alter the water chemistry and contribute to scale when combined with high mineral levels.
  8. Toiletry Products: Lotions, soaps, and other products can react with minerals in the water, aiding in scale formation.

Understanding these causes is the first step in fighting the hot tub scale. You can keep scale at bay and enjoy a clear, inviting hot tub by monitoring your water’s mineral content and pH level and ensuring proper circulation and chemical balance. Stay tuned for more on how to tackle and prevent this spa spoiler.

Step-by-Step Guide to Removing Hot Tub Scale

Remove Scale From Hot Tub

Removing the hot tub scale doesn’t have to be a daunting task. Follow this step-by-step guide, and your spa will be gleaming in no time.

Step 1: Drain the Hot Tub Begin by draining your hot tub. This gives you clear access to the surfaces where scale has made its home.

Step 2: Apply a Scale Remover Choose a scale remover suitable for your hot tub’s material. Apply it according to the manufacturer’s instructions, focusing on the affected areas. These removers usually need some time to work their magic, so you can move on to the next step while it sits.

Step 3: Clean the Filters While the scale remover does its job, take out the filters. Give them a good rinse, or soak them in a filter cleaning solution for a deeper clean. This helps ensure that when you refill your hot tub, the clean water won’t be immediately contaminated with leftovers from the scale.

Step 4: Scrub the Surfaces After the scale remover has had time to settle, grab a non-abrasive pad or brush and gently scrub the surfaces of your hot tub. Pay special attention to areas with visible scale buildup. Be thorough but gentle to avoid scratching the surface.

Step 5: Rinse Thoroughly Once you’ve scrubbed away the scale, rinse the hot tub’s interior thoroughly with clean water. You want to ensure all the scale remover and loosened scales are washed away.

Step 6: Refill and Balance the Water After rinsing, refill your hot tub with fresh water. Before you hop in, balance the water’s pH, alkalinity, and sanitizer levels to prevent the scale from making an immediate comeback.

Step 7: Regular Maintenance Moving forward, stick to a regular maintenance schedule. Test and adjust your water chemistry weekly, clean your filters regularly, and consider using a water softener or scale prevention product to keep that scale at bay.

With these steps, you’ll not only remove the existing scale but also take proactive measures to prevent future buildup. Enjoy your scale-free hot tub!

Scale Remover Types

Here’s a list of three types of scale removers that can help you keep your hot tub free from scale buildup:

  1. Citric Acid-Based Removers: These are natural, non-toxic scale removers that use the power of citric acid — found in lemons and limes — to break down calcium deposits. They are eco-friendly and safe for most hot tub surfaces.
  2. Vinegar Solutions: White vinegar is a household item that also effectively removes scale. It’s especially good for mild scale buildup and for those who prefer a DIY approach. It’s gentle and natural and can be used for regular maintenance.
  3. Commercial Scale Removers: Numerous commercial products are specifically designed to combat scale in hot tubs and pools. These often contain more potent chemicals and should be used according to the manufacturer’s instructions for the best results. They’re formulated to tackle tougher scale problems and are widely available at pool supply stores.

Scale Removers – Recommended Products

Here are three commercially available scale remover products designed for use in hot tubs and pools:

BioGuard Scale Inhibitor


BioGuard Scale Inhibitor: This is a product specifically formulated to prevent scale build-up on surfaces by inhibiting the formation of scale caused by hard water.

Leisure Time B-02 Defender Liquid


Leisure Time Spa Defender: An effective scale inhibitor that manages to prevent scale formations and aid in the removal of existing scales in hot tubs and spas.

SpaGuard Stain and Scale Control


SpaGuard Stain and Scale Control: A product that helps prevent scale by removing minerals from the water, which are responsible for causing scale on the surfaces of your hot tub.

Always check the product’s compatibility with your hot tub materials when using any scale remover to avoid any damage. Regular use as part of your maintenance routine can help prevent scale from taking hold in the future.

Hard water buildup

Understanding the Role of Hard Water in Scale Buildup

Hard water is the leading actor in the story of scale buildup in hot tubs. It’s chock-full of minerals like calcium and magnesium, which are great for our health but problematic for hot tub surfaces. These minerals get left behind as the water heats and evaporates, clinging to the sides of your spa as scale.

The warmth of the hot tub increases evaporation and mineral concentration, encouraging these minerals to come out of solution and form scale. This can be quite an issue, especially if your local water supply is naturally hard. Heated, circulating water exacerbates this natural process, leading to the stubborn, crusty deposits known as scale.

Combatting scale buildup starts with understanding that hard water needs to be managed. Water softeners, proper water treatment, and regular hot tub maintenance can prevent the minerals from staging a takeover, keeping your hot tub inviting and scale-free.

Read more on…

How to Soften Hot Tub Water? 

The Impact of Highly Alkaline Water on Your Spa

Highly alkaline water in your spa can be quite a troublemaker. When the pH of your hot tub water drifts above 7.6 and total alkalinity (TA) above 120 parts per million, it becomes a welcoming environment for scale to form. This high alkalinity can lead to the minerals in the water becoming less soluble, and as a result, they start to settle out and cling to the surfaces of your spa, creating that unsightly scale.

The effects of this alkaline water go beyond just the visual nuisance. It can interfere with the efficiency of your hot tub’s heating system and even shorten the lifespan of the spa components. Scale deposits can clog filters and jets, affecting water flow and heating, making your spa work harder than it needs to, which can ramp up energy costs and maintenance efforts.

Balancing your spa’s pH is essential for preventing these issues. Regular testing and adjusting of your hot tub’s water chemistry can keep the alkalinity in check. It’s a simple step that can save you from the headaches of scale buildup and keep your spa running smoothly for those relaxing soaks.

Body Oils and Contaminants in Hot Tubs

Body oils and contaminants can significantly impact hot tub scale formation. When these substances enter the hot tub water, they can interact with the minerals present, leading to the formation of hard, crusty deposits on the surfaces of the tub, jets, and plumbing. These deposits, known as hot tub scale, can cause various problems, including reduced water flow, increased energy consumption, and damage to equipment.

How Body Oils and Contaminants Contribute to Scale Formation

Body oils and contaminants can contribute to hot tub scale formation in several ways:

  • Emulsification: Body oils and contaminants can act as emulsifiers, allowing minerals to remain suspended in the water for longer periods. This increases the likelihood of mineral precipitation and scale formation.
  • Chemical Reactions: Body oils and contaminants can react with minerals in the water, forming new compounds that can contribute to scale formation.
  • Organic Matter: Body oils and contaminants provide organic matter, which can act as a binding agent for minerals, facilitating the formation of scale deposits.

Combating Body Oils and Contaminants

To combat body oils and contaminants and minimize their contribution to hot tub scale formation, consider implementing these measures:

  • Shower Before Entering: Showering before entering the hot tub removes dirt, oils, and other contaminants from the body, reducing their introduction to the water.
  • Limit Lotions and Oils: Avoid applying lotions or oils before entering the hot tub, as these substances can contribute to scale formation.
  • Maintain Proper Water Balance: Regularly test and adjust the hot tub water’s pH, total alkalinity, and calcium hardness levels to ensure they are within the recommended ranges.
  • Use a Hot Tub Skimmer: Regularly skim the hot tub’s surface to remove floating debris, body oils, and contaminants.
  • Clean the Hot Tub Filter: Clean the hot tub filter regularly to remove trapped contaminants and ensure proper water filtration.

By following these practices, you can minimize the impact of body oils and contaminants on hot tub scale formation and maintain a clean, healthy, and enjoyable spa experience.

The Unexpected Effects of Toiletry Products on Hot Tub Scale Formation

While hot tub scale is primarily caused by mineral deposits in the water, certain toiletry products can also contribute to its formation. These products can introduce additional chemicals and compounds into the water, altering its balance and promoting the precipitation of minerals onto surfaces.

Shampoos and Conditioners

Shampoos and conditioners can contribute to hot tub scale formation, especially those containing harsh chemicals or heavy fragrances. The surfactants in these products can emulsify oils and other contaminants, keeping them suspended in the water for longer periods and increasing the likelihood of mineral precipitation.

Soaps and Lotions

Soaps and lotions, particularly those containing moisturizing oils or shea butter, can also contribute to scale formation. These substances can form a film on the surface of the water, trapping minerals and facilitating their deposition.

Suntan Lotions

Sunscreen lotions, especially those containing zinc oxide or titanium dioxide, can also contribute to scale formation. These mineral-based ingredients can react with other chemicals in the water, leading to the formation of hard deposits.

Minimize Toiletry Product Use

To minimize the impact of toiletry products on hot tub scale formation, encourage showering before entering the hot tub to remove dirt, oils, and other contaminants. Avoid using excessive amounts of shampoos, conditioners, soaps, lotions, or suntan lotions when using the hot tub.

Rinse the Hot Tub

Rinsing the hot tub regularly with fresh water helps remove accumulated debris, body oils, and contaminants, reducing the likelihood of scale formation.

Maintain Proper Water Balance

Regularly testing and adjusting the hot tub water’s pH, total alkalinity, and calcium hardness levels to ensure they are within the recommended ranges helps prevent scale formation.

Use a Hot Tub Skimmer

Regularly skimming the surface of the hot tub removes floating debris, body oils, and contaminants before they can sink to the bottom and contribute to scale formation.

Clean the Hot Tub Filter

Cleaning the hot tub filter regularly removes trapped contaminants and ensures proper water filtration, preventing the buildup of scale-forming substances.

Strategies for Preventing Hot Tub Scale Before It Starts

Preventing the hot tub scale is all about proactive measures. Here are some strategies to keep scale at bay:

1. Balance the Water Chemistry: Regularly check and maintain the pH and alkalinity levels within the ideal range. Aim for a pH level between 7.4 and 7.6 and alkalinity between 100 to 150 ppm.

2. Soften the Water: If you have hard water, consider using a water softener to reduce mineral content before it enters your hot tub. This can prevent the minerals from accumulating and forming scale. Use a water softener.

3. Use Scale Inhibitors: Incorporate a scale prevention product into your routine maintenance. These inhibitors work by keeping the minerals dissolved in the water, preventing them from crystallizing on the tub’s surfaces.

4. Regular Cleaning: Keep the hot tub clean by wiping down surfaces and vacuuming the bottom regularly. This removes any potential scale-forming minerals before they can attach to the tub.

5. Filter Maintenance: Clean your hot tub’s filters regularly to ensure efficient water circulation and removal of debris, which can carry minerals that contribute to scale.

6. Proper Water Circulation: Make sure your hot tub’s water is circulating properly. Stagnant water is more likely to allow scale to form.

7. Pre-Treatment of Fill Water: Treat the water with a pre-filter when filling your hot tub. These filters can remove a significant amount of the minerals that cause scale.

8. Regular Draining: Depending on usage, completely drain and refill your hot tub every 3 to 4 months to prevent mineral buildup.

By following these strategies, you can reduce the likelihood of scale formation and ensure your hot tub remains a clean, inviting place to relax.

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Final Thoughts 

Preventing and removing scale from your hot tub is essential for maintaining a pristine soaking environment and prolonging the life of your spa. It starts with understanding your water’s chemistry and taking preemptive steps to ensure that the water remains soft and well-balanced. Regularly testing and adjusting pH and alkalinity levels, utilizing water softeners, and incorporating scale inhibitors into your maintenance routine can significantly mitigate scale buildup.

When scale does appear, tackle it head-on by draining the tub, applying a non-abrasive scale remover, and scrubbing gently to restore the hot tub’s surfaces. By staying vigilant with these practices and keeping the water chemistry and filtration system in check, you can keep scale at bay and ensure your hot tub remains a welcoming retreat for relaxation and enjoyment.

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