Considering a saltwater hot tub? Pros and cons

Saltwater in a hot tub? When it comes to hot tubs, the traditional method of keeping the water clean and clear has been through the use of harsh chemicals like chlorine. However, in recent years, an alternative method has gained popularity: saltwater hot tubs.

By using a saltwater system, hot tub owners can enjoy a more natural and gentler approach to water treatment. But is a saltwater hot tub the right choice for you?

In this blog post, I’ll explore the pros and cons of saltwater hot tubs, so you can make an informed decision about whether this innovative system is the best fit for your lifestyle and preferences. So, whether you’re a seasoned hot tub owner or considering your first dip, read on to learn more about the benefits and drawbacks of a saltwater hot tub.

 

What is a Salt Water Hot Tub?

A saltwater hot tub, also known as a chlorine generator hot tub or a mineral spa, is a type of hot tub that uses a salt chlorine generator to sanitize the water instead of traditional chlorine or bromine. The salt chlorine generator converts salt (sodium chloride) into chlorine (sodium hypochlorite) through a process called electrolysis. This chlorine then sanitizes the water, killing bacteria and other microorganisms.

Advantages of Using a Saltwater Hot Tub

Saltwater hot tubs offer several advantages over traditional hot tubs:

1. Softer, gentler water: The chlorine produced by the generator is milder than traditional chlorine, which means the water feels softer and is kinder to your skin and eyes.
   2. Reduced chemical odor: If you’re not a fan of the strong “pool” smell, you’ll be glad to know that saltwater hot tubs have a much subtler scent.
   3. Lower chemical usage: Because the generator does most of the heavy lifting, you’ll use less chlorine overall. It’s a win for the environment—and for your wallet over time.
   4. Increased buoyancy: The salt in the water gives you a bit of a floaty feel, making relaxation even easier.
   5. Easier maintenance: The salt chlorine generator automates much of the water care, cutting down on your to-do list.

Disadvantages of a Saltwater Hot Tub

That said, saltwater hot tubs aren’t perfect, and there are a few drawbacks to consider:

1. Higher upfront cost: These systems tend to cost more to buy and set up than traditional hot tubs.
   2. Increased risk of corrosion: Saltwater can be tough on certain metals, so you might need to keep a closer eye on maintenance to avoid wear and tear.
   3. Potential for algae growth: Saltwater hot tubs are a bit more prone to algae, which means occasional cleanings might be necessary.
   4. Long-term maintenance needs: While easier day-to-day, the corrosive nature of saltwater might mean more upkeep in the long run.

In a nutshell, saltwater hot tubs are a fantastic option for anyone looking for a more natural, skin-friendly, and eco-conscious way to enjoy a soak. They’re also great for those sensitive to chlorine or prone to irritation. However, the higher initial cost and potential for increased maintenance are worth keeping in mind when weighing your options. 

How Does a Salt Water Hot Tub Work?

A saltwater hot tub, also known as a chlorine generator hot tub or a mineral spa, utilizes a salt chlorine generator to sanitize the water. This method differs from traditional hot tubs that rely on chlorine or bromine for sanitation.

The core of a saltwater hot tub’s operation lies in a process called electrolysis. This involves passing an electric current through salt (sodium chloride) dissolved in the hot tub water. During this process, the sodium chloride molecules split into sodium (Na+) and chloride (Cl-) ions. The chloride ions then react with each other and with water molecules to form hypochlorous acid (HOCl), which is a potent sanitizer.

The generated hypochlorous acid effectively kills bacteria, viruses, and other microorganisms, ensuring the cleanliness of the hot tub water. The level of chlorine production is regulated by the salt chlorine generator, maintaining a consistent sanitizing effect without the harshness of traditional chlorine.

Here’s a simplified breakdown of the electrolysis process in a saltwater hot tub:

1. Salt (NaCl) dissolves in the hot tub water.

2. An electric current is passed through the salt solution.

3. The salt molecules dissociate into Na+ and Cl- ions.

4. Cl- ions react with each other and with water molecules to form HOCl (hypochlorous acid).

5. HOCl acts as a sanitizer, killing bacteria, viruses, and other microorganisms.

6. The salt chlorine generator monitors and controls the level of HOCl in the water.

7. The sanitized water circulates through the hot tub jets, providing a relaxing and clean soaking experience.

How Much Does a Saltwater Hot Tub Cost, and Will It Save You Money?

Upgrading your hot tub to a saltwater system is a decision worth careful consideration. While the initial expense is higher than traditional systems, the benefits can often justify the investment. Let’s explore the costs and potential savings to determine if a saltwater system is the right choice for you.

Cost Breakdown of a Saltwater System

The central component of a saltwater hot tub system is the generator, often called a salt chlorinator or salt cell. The price depends on the model, features, and quality:

• Basic Models: These systems, priced between $300 and $700, handle the essential task of converting salt into chlorine to maintain water sanitation.
• Mid-Range Models: For $700 to $1,200, mid-tier systems offer features like self-cleaning mechanisms, digital displays, and more precise chlorine production control.
• High-End Models: Advanced options start at $1,200 or more, providing longer lifespans, enhanced performance, and cutting-edge technology.

Additional costs to consider include:

• Installation: Professional installation ensures proper setup, though it adds to the upfront expense. DIY is an option for those with expertise.
• Maintenance: Regular tasks include testing water, cleaning the salt cell, and replacing it every 3 to 7 years, depending on usage and model quality.
• Salt: Pool-grade salt is required to maintain the proper levels, and while it is inexpensive, it contributes to recurring costs.
• Energy Usage: Operating the salt generator increases electricity consumption slightly, adding to ongoing expenses.

Choosing a system that matches your hot tub’s water capacity is crucial. Consulting with your manufacturer or a professional technician ensures compatibility and optimal performance.

Can You Save Money on Chemicals with a Saltwater System?

A significant advantage of saltwater systems is their potential to reduce chemical costs. Unlike traditional hot tubs that rely on frequent purchases of chlorine tablets or liquid chlorine, saltwater systems generate chlorine through affordable salt. Here’s how the costs compare:

• Initial Investment: While salt systems are costlier upfront due to the generator, they can offset these costs over time.
• Ongoing Savings: Salt is far less expensive than traditional chlorine products. According to the Pool and Hot Tub Alliance, switching to a salt system can lower chemical costs by up to 50%.

Factors Affecting Savings

The amount you save with a saltwater system depends on several variables:

• Hot Tub Size: Larger tubs demand more chlorine, making the cost difference more pronounced.
• Usage Frequency: Frequent use increases chlorine consumption, amplifying the savings from a salt system.
• Chemical Costs: In areas where chlorine is expensive, the switch to salt systems offers more substantial financial benefits.

While saltwater systems come with a higher initial price tag, they often pay off in the long run through reduced chemical costs, lower maintenance demands, and improved water quality. These systems also provide a more natural soaking experience and are generally more eco-friendly than their traditional counterparts.

Maintaining Your Saltwater System

Proper maintenance of a saltwater system is essential to ensuring its longevity, efficiency, and cleanliness. Whether you’re adjusting chlorine levels, changing the water, or keeping the system running smoothly, consistent care is vital for a safe and enjoyable hot tub experience. Below, we break down key aspects of maintaining your saltwater system.

How to Increase Free Chlorine in a Saltwater Hot Tub

Increasing the free chlorine level in a saltwater hot tub is essential to ensure that the water stays clean and sanitized. Follow these steps for optimal chlorine management:

1. Check Current Levels: Start by testing the water for free chlorine, pH, and total alkalinity using a reliable test kit or test strips. Understanding these levels is important, as pH and alkalinity can affect chlorine’s effectiveness.
2. Check the Salt Cell: Ensure the salt cell is clean and functioning correctly. A dirty or malfunctioning salt cell can result in inadequate chlorine production, so regular cleaning and maintenance are key.
3. Increase Chlorine Output: Most saltwater systems allow you to adjust the chlorine output. Check your system’s user manual to learn how to increase the chlorine production rate. This may involve navigating the control panel or adjusting settings.
4. Run the System Longer: If your system’s chlorine production depends on runtime, consider increasing the daily operating hours to produce more chlorine. Just keep in mind that this will use more electricity.
5. Add Salt: If the salt concentration is low, the salt cell won’t produce enough chlorine. Add the appropriate amount of pool-grade salt to reach the recommended concentration, typically between 2,500 and 3,500 ppm. Always follow the manufacturer’s guidelines.
6. Shock the Hot Tub: Occasionally shocking the water can quickly raise chlorine levels. Use a non-chlorine shock or one compatible with your saltwater system. Follow the recommended dosage and allow time for the system to work.
7. Balance pH and Alkalinity: Proper pH (7.4-7.6) and total alkalinity (80-120 ppm) levels ensure chlorine works effectively. Regular testing and adjustment of these levels help maintain a healthy water environment.
8. Ensure Proper Water Circulation: Make sure the jets are working efficiently to ensure chlorine is evenly distributed throughout the water.
9. Regular Maintenance: Regularly clean the filter and salt cell, and check other components of the saltwater system. A well-maintained system operates more efficiently, improving chlorine production.
10. Monitor and Adjust: After making adjustments, retest the water a few hours later to ensure that the chlorine level is where it should be. If needed, make further adjustments to maintain the desired chlorine levels.

By following these steps, you’ll maintain the ideal chlorine balance for clean, clear, and safe water.

How Often Should You Change the Water in a Saltwater Hot Tub?

Changing the water in your saltwater hot tub is an essential part of maintenance. The frequency can vary based on factors like water quality, usage patterns, and system maintenance. Here are some factors to consider:

1. Water Quality: If the water becomes cloudy, has a strong odor, or feels slimy, it’s time to replace the water. These signs usually indicate a buildup of contaminants or ineffective sanitization.
2. Regular Testing: Regularly test your water for chlorine, pH, and salt levels. If you find it difficult to maintain proper chemical balance despite regular adjustments, it may be time for a water change.
3. Seasonal Changes: Some owners prefer to change the water at the start of each season, like spring or fall. This helps reset the system and prepare for the new season with fresh water.
4. Maintenance Practices: Consistently cleaning filters, maintaining the salt cell, and ensuring proper water circulation can extend the time between water changes.
5. Salt Concentration: If salt levels rise too high, they can reduce the efficiency of the saltwater system. Periodically measure salt levels and consider a partial water change if the concentration exceeds the recommended range (2,500 to 3,500 ppm).
6. TDS Levels: Total Dissolved Solids (TDS) build up over time and can affect water quality. If TDS levels become significantly elevated, consider changing the water.
7. Manufacturer Recommendations: Always refer to the manufacturer’s guidelines for water change recommendations, as different systems may have specific requirements.

Water changes should be done thoughtfully to minimize environmental impact. Be sure to follow local water conservation regulations when disposing of old hot tub water.

Signs That Your Saltwater System Needs Servicing

Regular servicing ensures that your saltwater system continues to operate efficiently. Be on the lookout for these signs that your system may require professional attention:

1. Water Quality Issues:
   • Cloudy or discolored water
   • Excessive foam or suds
   • Algae growth (green or slimy patches)
   • Unpleasant odors (strong chlorine smell or other funky smells)
2. Performance Problems:
   • Reduced heating efficiency
   • Weaker jets or inconsistent bubbles
   • Unusual noises (grinding, humming, or banging)
   • Electrical issues (sparking, flickering lights, or tripping circuits)
3. Salt Cell and Generator Problems:
   • Reduced chlorine production, even with proper salt concentration
   • Mineral scaling or corrosion on the salt cell
   • Warning lights or error messages indicating issues with the salt cell or generator
4. General Maintenance Guidelines:
   • Regularly schedule professional service, ideally once a year, for a thorough inspection.
   • Follow your manufacturer’s cleaning, maintenance, and troubleshooting instructions.
   • Don’t ignore issues—acting quickly can prevent further damage and costly repairs.

By recognizing the early signs that your saltwater system needs servicing, you can ensure that your hot tub remains in top condition for years to come.

Can I Add a Saltwater System to My Hot Tub?

Yes, it’s possible to retrofit a standard hot tub with a saltwater system. These systems, also known as salt chlorinators or salt cells, provide a natural and efficient way to maintain water quality. Here’s how to properly install a saltwater system in your hot tub:

• Placement: The salt cell should be installed after the filter and just before the water returns to the tub via the jets. This setup ensures that the water is filtered before undergoing chlorination.
• Filtration First: Positioning the filter before the salt cell removes debris and impurities, allowing the salt cell to operate more effectively and treat clean water.
• Efficient Chlorination: By placing the salt cell in the flow path after the filter, the generated chlorine is evenly distributed throughout the hot tub, ensuring consistent water sanitation.
• Circulation: Proper placement aligns with the hot tub’s circulation system, promoting even distribution of chlorinated water for an enjoyable soaking experience.

Always follow the manufacturer’s instructions for installing a saltwater system to ensure compatibility with your specific hot tub model. If you’re unsure about the process, seeking professional assistance can help guarantee a safe and effective installation.

By upgrading your hot tub to a saltwater system, you can enjoy a more natural water treatment method, reduced reliance on traditional chemicals, and a luxurious soaking experience. Whether retrofitting an existing tub or investing in a new saltwater-compatible model, this upgrade can enhance your relaxation and simplify hot tub maintenance.

How are Saltwater Systems for the Environment?

Saltwater hot tubs offer several environmental benefits, particularly in comparison to traditional chlorine or bromine systems. One of the main advantages is the reduced use of harsh chemicals, as saltwater generators produce their own sanitizer through electrolysis. 

This minimizes the need for additional chemicals, which can harm aquatic life and pollute groundwater when disposed of improperly. Additionally, saltwater systems tend to generate lower levels of free chlorine, leading to a milder smell and less irritation for users. 

However, saltwater systems are not without their environmental concerns. The periodic addition of salt requires energy-intensive extraction processes, and if not disposed of correctly, it can contaminate marine environments. While they are generally more energy-efficient than older chlorinator models, the electricity needed for the electrolysis equipment can negate some of the environmental benefits if sourced from polluting energy grids. 

Moreover, saltwater systems still produce chlorine through electrolysis, contributing to its environmental presence. Responsible disposal of the salt cells, which eventually wear out, is also crucial to minimize their impact. 

Overall, saltwater hot tubs can be an eco-friendly option depending on the technology used, energy sources, and responsible maintenance practices, but it’s important to consider all factors before making a choice.

Alternative to a Saltwater System

For those seeking an alternative to saltwater systems in hot tubs, ultraviolet (UV) water treatment systems present a viable option. UV systems use a specialized lamp to emit UV-C radiation, which effectively destroys harmful bacteria, viruses, and other contaminants by disrupting their DNA and preventing reproduction. 

A major advantage of UV systems is that they eliminate the need for chemicals or salts, which can be harsh both on the skin and the environment, making it a more natural and eco-friendly choice for hot tub users. A

Additionally, UV systems can reduce maintenance demands since they do not require the frequent monitoring and chemical adjustments needed by traditional chlorine-based systems. However, it’s important to note that UV systems may not provide complete sanitation on their own, and may still require supplementary treatment methods, such as chlorine, bromine, or active oxygen in smaller quantities. 

UV lamps also need to be replaced every 1-2 years to maintain their effectiveness. Overall, UV water treatment systems offer a cleaner, greener alternative to saltwater systems, providing a balanced approach to keeping your hot tub safe and enjoyable without the need for harsh chemicals.

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Thanks - Andi

 

Hi, Andi here. I own Buildahottub.com and also write all of the articles and info pages on the site. Some years back now, I built my own hot tub but struggled to find the information I needed. So, once my tub was complete, I started this website to help others in their own pursuit of hot tub and plunge pools DIY building information.

Fast forward to 2025, I've helped over 1400+ DIY customers just like you all over the world build hot tubs and pools. Have a good look around the site, there are lots of resources here. Please do get in touch if I can help you. - Cheers, Andi