Every hot tub needs a sanitisation system to keep the water clean and safe. The two most common options are saltwater and chlorine, and your choice affects how the water feels on your skin, how much time you spend on maintenance, and what you pay over years of ownership.

A chlorine system works by manually adding chlorine chemicals to your water regularly to kill bacteria and keep it balanced. A saltwater system, however, uses a salt chlorination cell built into the tub’s plumbing that automatically converts dissolved salt into chlorine. You still get chlorine in the water, but your tub generates it for you instead of you adding it by hand.

Saltwater systems also cost more upfront, but you’ll get softer water, less hands-on maintenance, and lower chemical costs over time. Chlorine systems are cheaper to set up and easier to source, but they require more consistent attention, and chemical costs add up. In the sections below, we’ll help you work out which one fits your situation.

The Cost Picture Over Time

Saltwater systems typically cost around £70–£75 per year in replacement cartridges. A full chlorine treatment regime that covers sanitiser, pH balancers, and shock treatments runs between £190 and £285 annually. Across five years of ownership, that’s a difference of £575 to £1,050 in chemical costs alone.

Water changes also increase the costs. Saltwater hot tubs need a full drain and refill roughly once a year, which reduces the volume of chemicals going into your water and simplifies your maintenance calendar. For chlorine systems, you only need to change the water every three to four months.

The Environmental Impact

If your goal is to reduce your household chemical footprint, saltwater systems are the way to go. Saltwater systems use far fewer manufactured chemicals over the life of your spa, which eliminates the monthly cycle of buying chlorine bottles, pH balancers, and shock treatments.

What Chlorine Still Does Well

Chlorine remains the more accessible choice for easy adjustments. Products are widely available, dosing is well understood, and any hot tub engineer or pool specialist will be familiar with the system. If something goes out of balance, a chlorine-treated tub is usually quicker to correct without specialist equipment.

Making the Right Choice for Your Garden

For most homeowners who want a relaxing, low-maintenance experience with softer water and less chemical handling, a saltwater system is a better choice. But if you prefer flexibility, a lower initial outlay, or a more hands-on approach to water chemistry, a chlorine system may be a more natural fit.

The sections below break down each option in detail so you can match the right system to your specific situation.

How We Compared Saltwater and Chlorine Hot Tubs

Both systems sanitise water effectively, but they differ considerably in the day-to-day reality of ownership, which is exactly where most buyers feel least informed before committing.

To give you a genuinely useful comparison, we assessed both systems across four areas that matter most to buyers:

• Upfront and ongoing costs
• Maintenance demands
• The bathing experience
• Environmental considerations

Every option in this guide is evaluated against those same four areas, in the same order, so you can make like-for-like judgements without hunting through scattered paragraphs.

Let’s get right into it!

Upfront and Over Time Costs

Saltwater systems cost £400 to £1,000 more than a comparable chlorine unit, because you’re paying for a dedicated salt chlorination cell built into the tub’s plumbing and filtration, on top of the tub itself.

You also need to factor in:

• Granules or tablets bought through the season (roughly £150–£250 for regular use)
• Weekly non-chlorine shock to oxidise body oils and organics (£40–£60)
• pH and alkalinity adjusters (£30–£50)
• Test strips (£15–£25).

In total, that’s £235–£385 a year.

For saltwater, the ongoing consumables are cheaper:

• Salt itself (£20–£40 a year)
• pH-lowering product, and more of it than a chlorine owner needs, since the electrolytic reaction produces sodium hydroxide as a byproduct and pushes pH upward on its own (£40–£70)
• Test strips (£15–£20)
• A replacement salt cell every two to five years, at £200–£600 at a time, which works out to roughly £40–£300 a year depending on how long a given cell lasts

In total, that’s roughly £115–£430 a year once you factor in the cell. Also, saltwater hot tubs need a full drain and refill about once a year, while chlorine systems usually need one every three to four months.

Maintenance:

Saltwater systems automate most of the sanitisation process through electrolysis, which continuously converts dissolved salt into chlorine. That cuts down on manual dosing, but it doesn’t eliminate maintenance.

Because the electrolytic reaction also produces sodium hydroxide as a byproduct, pH tends to drift upward over time, so you’ll need more pH-lowering product than a standard chlorine system to stop scale building up on heaters and jets. The salt cell itself also needs periodic inspection and descaling, especially if you’re on hard mains water, roughly every three months.

Chlorine systems require weekly water testing and manual adjustments to sanitiser, pH, and shock levels, especially in summer when heavier bather load and UV exposure burn through chemicals faster.

The Bathing Experience

This is where saltwater hot tubs earn some of their strongest praise. Their lower salt concentration gives the water a noticeably softer, silkier feel against the skin, eyes, and hair. By comparison, chlorinated water can strip natural oils from skin and hair with repeated exposure, which may leave regular swimmers dry, irritated, or duller over time. If you have sensitive skin, the gentler feel can make soaking more comfortable, especially if you use the hot tub several times a week. Saltwater systems also produce chlorine gradually through electrolysis, which helps to maintain a steadier sanitiser level rather than the concentration spikes that can follow manual dosing or shock treatments.

Read more: How long you should stay in a hot tub

Comparison Table: Saltwater vs Chlorine Hot Tubs

Benefits of Saltwater Hot Tubs

The most common reason people move toward saltwater systems is how the water feels on your body. Also, if chlorinated water irritates you after extended soaks, saltwater systems are a much better alternative. The sodium in a saltwater hot tub softens the water to create a more natural and less harsh environment for your skin, eyes, and hair.

Other benefits are:

Low Running Costs

At first, you pay more to buy and set up a saltwater system than a chlorine hot tub because you must purchase a salt chlorinator unit in addition to the tub itself. Over time, however, your ongoing maintenance costs fall because the system generates chlorine from salt rather than relying on frequent manual additions of chlorine products.

Easy Maintenance

Saltwater systems are easy to maintain. The salt chlorinator produces chlorine from the salt in the water, so you need to measure and add fewer separate sanitiser doses. Once the water reaches the correct balance, you only need to run routine pH checks and adjustments.

The salt chlorinator cell also needs periodic inspection and cleaning. Mineral deposits can build up on the cell over time, especially where the water contains high levels of calcium. Regular descaling helps the cell maintain its performance and service life, so saltwater does not mean maintenance-free water care.

Tip:

If you plan to add a salt system to an existing hot tub, check the manufacturer’s specifications first. The tub, plumbing, heater, pumps, and other components must be compatible with saltwater systems.

Perfect for Building a Broader Home Wellness Routine

A saltwater hot tub pairs well with a broader home recovery routine. Many of our customers who invest in a hot tub for relaxation and muscle recovery also explore complementary options such as infrared saunas for dry heat therapy or the Barra Cold Plunge for contrast therapy to create a layered approach.

Read more: Benefits of using a sauna and ice bath

Best Suited to Frequent, Family Use

Saltwater pays off most when a tub is used often by several people, which is exactly where the reduced maintenance and softer water matter most.

A family-sized model like the Equinox EQ570 Lite 5 Person Hot Tub is a good example of a saltwater setup. It runs on a standard 13A connection, and its app-based Spatech controls make it easy to check and adjust the system without opening a manual every time.

If you’re unsure whether a 13A or 32A supply suits your garden, read our guide on 13 Amp vs 32 Amp Hot Tub. As always, confirm saltwater compatibility with the manufacturer before converting or specifying a salt system on a particular model.

Benefits of Chlorine Hot Tubs

The most common reason people stick with chlorine is that it’s the system they already understand. It’s been the standard for decades, works reliably, and everything you need to run it is easy to find. If you’d rather have full manual control over your water than hand that job over to an automated cell, chlorine gives you that.

Other benefits are:

Lower Upfront Cost

Chlorine systems have no specialist equipment to install or replace, which keeps your starting cost lower than a saltwater setup. Granules, tablets, and test strips are affordable and available at almost any garden centre or pool supplier, so you don’t have to wait on specialist parts to get started.

Fast, Reliable Sanitisation

Dosed correctly, chlorine kills bacteria and clears the water quickly. This matters if you want to use your hot tub spontaneously rather than waiting for chemistry to rebalance. It also means you can respond quickly to a contamination event, like heavy use after a gathering, without needing specialist equipment to fix it.

Straightforward, Well-Understood Maintenance

Most owners settle into a routine that takes a few minutes a week: testing, adjusting sanitiser and pH, and shocking the water regularly to keep chloramines in check. It’s not complicated, just consistent, and any hot tub engineer or pool specialist will already know the system, so troubleshooting rarely needs specialist input.

Tip:

Chloramines, the compounds formed when chlorine reacts with sweat and other organic matter, are the main cause of that sharp chemical smell and skin or eye irritation. Shocking the water regularly, especially in summer or after heavy use, keeps them from building up and is the easiest way to avoid the issues that put people off chlorine in the first place.

Perfect for Flexible and Commercial Use

Chlorine is compatible with virtually every hot tub model, so there’s no need to check manufacturer guidance the way you would before adding a salt system. This makes it a practical choice for commercial buyers and holiday let operators too, since keeping consistent, verifiable sanitation records is simpler with a chemical and testing protocol most contractors and inspectors already know. Family-friendly, family-sized models such as the “Orca Leisure Sweetboro 5 Person Hot Tub” work well here.

How to Choose the Right Hot Tub for Your Needs

Families and frequent bathers:

If your hot tub will see regular use from multiple people — including children or anyone with sensitive skin — saltwater is the more comfortable long-term choice. The sodium in saltwater systems softens the water to create a gentler environment for your skin, eyes, and hair than conventional chlorine treatment. The higher upfront cost is a reasonable trade-off when daily comfort and reduced chemical handling are your priorities.

Budget-conscious buyers:

If you want a reliable, proven system without the premium entry cost, a chlorine hot tub remains a sound choice. Your running costs are predictable, replacement chemicals are widely available, and the maintenance routine is well-documented. The key is consistent water testing, which removes most variability in outcomes.

Eco-conscious and low-maintenance buyers:

Saltwater systems require fewer chemical additions over time and generate less packaging waste. If you prefer a simple routine and a low chemical load, a saltwater-converted or purpose-built saltwater hot tub fits that approach well.

Active recovery and wider wellness setups:

If your goal extends beyond relaxation to structured recovery, consider the broader picture. Many customers pair a hot tub with a cold plunge to create a contrast therapy setup at home.

The Bottom Line

Both systems keep your water safe. Saltwater costs more to set up but pays for itself over time through softer water, less hands-on maintenance, and steadier chemistry, which is why it tends to suit families, frequent bathers, and anyone with sensitive skin. Chlorine costs less to start, works with any hot tub, and gives you full manual control, which is why it remains the practical choice for budget-conscious buyers, occasional users, and commercial or holiday let operators who need a well-documented routine.

Neither is the objectively better system. The right one depends on how often you’ll use the tub, how hands-on you want to be with water care, and what you’re weighing that against: upfront cost or ongoing convenience. If you’re still unsure which fits your household, our team is available by phone, email, or live chat to talk it through.

FAQs

Is a saltwater hot tub actually chlorine-free?

No. A saltwater system still sanitises with chlorine; it just produces it continuously through electrolysis rather than adding it by hand. That’s why the water feels softer and smells less sharp, not because the chlorine is gone.

Is saltwater cheaper than chlorine in the long run?

It depends on the timeframe. Ongoing consumables are cheaper for saltwater, but once you factor in replacing the salt cell every two to five years, the two systems end up closer than the yearly chemical costs alone suggest.

Can I convert my existing chlorine hot tub to saltwater?

Sometimes, but not always. Not every hot tub-its plumbing, heater, and pumps- is built to handle a salt system, so check the manufacturer’s specifications before retrofitting one onto an existing tub.