What is a salt water hot tub? (Benefits, considerations and more)

Disclaimer - In this article, we’ve used brand names not affiliated with Jacuzzi Group. You can see the list of the brand owners at the bottom of this article. All information, including pricing and product details, was accurate at the time of writing (March 29, 2023) and may change without notice. 

What is a salt water hot tub? 

A salt water hot tub has a salt-chlorine generator that converts salt into chlorine.

This means you do not need to manually add sanitiser to the water to keep it clean. 

How does a salt water hot tub work? 

Salt water hot tubs are charged with salt, and the hot tub changes this to chlorine.  

The conversion from salt to chlorine occurs through electrolysis. This is the chemical reaction process that causes the end result – chlorine. 

What is the difference between chlorine (from a salt water system) and bottled chlorine? 

Chlorine produced by a salt water system is sodium hypochlorite.  

The difference with chlorine that you buy in a bottle (which is also sodium hypochlorite) is that it also contains additional chemicals such as cyanuric acid (CYA), known as stabiliser acid.  

When you remove this acid, you get chlorine without the irritations you can experience from bottled options, hence the salt-water system alternative. 

Why does bottled chlorine have added chemicals? 

The role of a stabiliser acid in bottled chlorine is to reduce the amount of chlorine that’s destroyed by the sun’s UV rays. 

Saltwater hot tub systems in the UK

Several hot tub brands offer the option of a salt water system. However, the main and most regarded system in the UK is the FreshWater™ Salt Water System, used by Hot Spring® and Caldera Spas®. 

Salt water hot tub benefits 

There are several benefits that come with using a salt water system in a hot tub. 

-No strong aroma - The chlorine produced is created naturally. This means you don’t get the harsh dry chemical smell that granules and tablets give off. 

-Kinder on your skin - Lower levels of chlorine. Skin is less likely to get irritated, turn red or get itchy. 

-Added buoyancy - Saltwater adds extra buoyancy to the water, so your body floats that little bit more. Easing pressure on the body and heightening the hydromassage.  

Salt water hot tub considerations 

Along with the benefits a saltwater system in a hot tub can bring, there are also some important factors to keep in mind too. 

-Cartridge replacement costs – Depending on use, how many people use the hot tub and how well maintained the hot tub is, some cartridge options, such as the HotSpring® FreshWater™ Salt Water system can last up to four months.  

However, if they are disposable cartridges, there is the added cost of buying refills. According to HotSpring® Central, replacement cartridges range in price from £95 to £270 (for a pack of three). 

-Corrosive nature of salt – For a salt water system to work well long-term in a hot tub, the correct levels or ppm of salt (parts per million) need to be maintained. Adding too much salt and exceeding the maximum ppm level can lead to harmful effects such as corrosion of metal elements, including the stainless steel fittings and bearings inside jets, as well as pumps and heaters. 

-Salt residue – If a build-up of calcium occurs, this will need to be cleaned and removed. 

-Maintenance - A salt water system still requires maintenance. This generally includes the testing of water, cleaning and replacing of cartridges, as well as emptying and refilling the hot tub water, and adding salt with the changeover of water.  

-Chemical usage - Certain stages of installing and using a salt water system can still require the use of chemicals, to boost water quality or to solve issues. 

Can any hot tub use salt water? 

Salt systems can only work in a hot tub that has a salt water system built into it. Most suppliers in the UK do not offer this. 

We recommend you speak to your retailer about what options are available to you.  



Can you buy automatic salt water systems for hot tubs? 

Salt systems are usually factory fitted or optional extras for a hot tub that is designed to use salt. 

Salt will always have to be manually added to a domestic hot tub. It is the conversion from salt to the sanitiser (chlorine or bromine) which is carried out by the electronic system. 

Does Jacuzzi® sell salt water hot tubs?

No Jacuzzi does not sell salt water hot tubs. The reason for this, is that salt water sanitisation within hot tubs are an innovation from another brand. We at Jacuzzi®, have our own, different methods for sanitisation which we innovated, such as CLEARRAY Active Oxygen™ which is exclusive to Jacuzzi®.

Can I use salt instead of chlorine in a Jacuzzi® Hot Tub? 

Jacuzzi does not recommend the use of salt in a Jacuzzi® Hot Tub. This is due to its corrosive nature that is not covered under the product warranty.  

However, with the Jacuzzi multi-stage filtration process and CLEARRAY Active Oxygen™ system, you can reduce the use of chlorine or bromine by up to half.

This provides similar benefits to what you will find with a salt water system – reduced chemicals and smell, and the flexibility to use whichever sanitiser works for you. 

Can I use salt water in a swim spa? 

Yes you can use salt water in a swim spa. However, like hot tubs, not all brands provide the option. If you look at Arctic Spas®, their swim spas can be equipped with a salt water system which delivers the benefits of a salt water pool.  

Currently Jacuzzi® Swim Spas are only compatible with chlorine or bromine.  

We recommend you speak to a salesperson about whether your preferred brand can use salt water in a swim spa. 

Pros of a salt water hot tub 

• Chlorine is automatically generated from the electrolysis of the salt water 
• Low maintenance - Less draining, checking and changing of the water 
• Kinder to skin 
• Less chemical smells 
• More buoyancy – Further reducing pressure on joints

Cons of a salt water hot tub 

• More expensive to purchase up front and potentially higher ongoing costs (e.g replacing cartridges) 
• Salt can be corrosive to parts of the hot tub when not used properly 
• The strength of the chlorine is not as powerful as using chemical tablets or granules 
• Cost of disposable cartridges for a salt water system can add up 
• Can be a more complicated start-up process  

Summary  

We hope this article has provided you with a thorough understanding of the initial need to know information on salt water hot tub systems.

By covering the benefits, considerations, costs and more, you should have a better idea of what’s involved with this system type, and if it could be the best fit for you. 

Want to delve a bit deeper into chlorine options? Chlorine and bromine are often compared against each other. Read this article for a clear understanding of these two sanitiser options.  

For more information on our range of Jacuzzi® Hot Tubs, check out our Hot Tub Brochure which includes clear explainers about key features, product specifications and more.