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Man lifting the cover and checking the clear water of his Caldera Paradise spa

FRESHWATER® WATER CARE

Hot Tub Water Care

Water care is the part of hot tub ownership most shoppers know the least about, and it is where Hot Spring® and Caldera® genuinely stand apart. Every spa we sell runs one of three systems, and this page explains how each of them works.

Easier Water Care, Built Into Every Hot Tub We Sell

Keeping the water clean is the part of ownership most shoppers worry about, and it's where Hot Spring® and Caldera® pull ahead. Their spas can make their own chlorine from salt, so the water feels soft and can go up to a year between changes. On 2024-and-newer premium models, the spa also tests its own water every hour and tells you what it needs.

Shop Hot Tubs by Water Care

Pick a system to see every model that runs it, then narrow the results by size or price. Every model links to its full detail page.

The FreshWater® Salt System

Of everything that separates a Hot Spring® or Caldera® spa from other hot tubs, the salt system changes daily life the most, and it is the feature we explain to every customer. On most hot tubs, you manage the water chemistry yourself, testing and adding chemicals throughout the week. A salt-system spa manages it for you.

How the system works

You dissolve a small amount of salt in the water once, at fill-up. A titanium cartridge built into the spa’s plumbing then converts that salt into chlorine continuously as the water circulates, a little at a time, all day. It makes the same chlorine you would otherwise measure and pour by hand, and it makes it at the level the water needs. The cartridge also carries silver, a natural antimicrobial that suppresses bacteria on its own, so the water needs less chlorine in the first place.

Softer water, far less dosing

Salt water feels softer on your skin and is gentler on swimsuits and hair. Because the system makes chlorine on its own, you add far fewer chemicals and spend less time testing and adjusting. Guests notice the difference the moment they get in.

Up to a year between water changes

Stable, self-managed water means you drain and refill far less often. The titanium cartridge is owner-replaceable about every four months with no tools, and that is most of the maintenance.

Which spas have it

Included on the Highlife® and Utopia® collections, and salt-ready on Limelight®, Hot Spot®, Paradise® and Vacanza®. See the full Salt System details.

Woman relaxing in the clear, soft water of a Caldera Paradise Reunion spa

Salt Water vs. Traditional Chlorine Care

Both routines keep the water sanitized. On a typical chlorine hot tub, you test the water with strips several times a week, measure and add chlorine by hand, shock after heavy use, and drain and refill every few months as the chemicals accumulate. With the FreshWater® Salt System, the routine and the result look like this.

Hand dropping a FreshWater Salt System titanium cartridge into the port of a Caldera spa, guided by the control panel
The routine. Drop in a fresh titanium cartridge about every four months, no tools needed, and check the water with a test strip every week or so. After heavy use, the Boost button raises chlorine output for 24 hours on its own.
Couple relaxing in the clear water of a Hot Spring Highlife Vanguard spa
The result. Softer water that stays clean and balanced with almost nothing from you, and with proper care you drain and refill about once a year.

FreshWater® IQ

FreshWater IQ adds hourly water testing and one-touch dosing on top of the salt system. A built-in sensor measures chlorine, pH, and salt every hour, the spa shows you what it needs on the control panel or the app in simple color-coded terms, and it corrects pH at a tap, so even the strip check mostly disappears.

Available on 2024-and-newer Highlife®, Limelight®, Utopia® and Paradise® models.

Explore FreshWater IQ
FreshWater IQ control panel monitoring hot tub water
Caldera Fantasy plug-and-play spa on a patio

FROG® Water Care for Plug-and-Play Spas

Plug-and-play Freeflow® and Fantasy® spas use the FROG® sanitizing system: pre-filled cartridges that release sanitizing minerals and chlorine and self-regulate to your spa’s needs. It keeps chlorine steady without daily measuring.

Explore FROG @ease

Salt Water Hot Tub Maintenance

This is the complete calendar, the same routine we walk every new owner through. There is less of it than most shoppers expect.

Most days

Nothing is required on a normal day. The salt system generates chlorine around the clock, so the water stays hot, sanitized, and ready whenever you want to get in, all year round.

Every week or so

Check the water with a test strip to confirm everything is in range, and rinse the filter about once a month. Together they take a few minutes.

About every four months

Swap the titanium cartridge. It is a drop-in replacement you do yourself, with no tools and no service call, and a three-pack of cartridges covers roughly a year.

About once a year

Drain, rinse, and refill. Because the salt system keeps the water stable in between, this is the only large water job on the calendar.

Frequently Asked Questions

Here are answers to the questions we hear most about hot tub water care. The Learning Center covers each one in depth.

Is salt water better than chlorine?

A salt system still sanitizes with chlorine, it just makes it for you from dissolved salt instead of asking you to add it by hand. The water feels softer, you dose far less, and you go up to a year between water changes.

Is the water salty, like the ocean?

No. The system runs on a small fraction of the salt found in seawater, so the water feels soft rather than salty. If you want to check for yourself, any of our three showrooms can let you feel salt-cared water in person.

How much maintenance does a salt spa need?

Very little. Replace the titanium cartridge about every four months, rinse the filter on a normal schedule, and check the water now and then. FreshWater® IQ reduces even that by testing hourly and dosing at a tap.

Do I need to be good at chemistry?

No. The system is designed so the spa holds its own sanitizer steady, and your part is an occasional test strip that takes under a minute to read. We walk every new owner through the routine, and you can always call us if a reading looks off.

What if my tap water is hard?

Hard fill water is worth catching early, because excess minerals shorten the cartridge’s life and can scale the heater. The fixes are simple. Depending on how hard your tap water is, that can be a pre-filter that attaches to the garden hose at fill-up or a softening pillow that sits in the water, and we will point you to the right one.

Can I add salt water care to a plug-and-play spa?

Freeflow® and Fantasy® spas are built around the FROG® cartridge system rather than the salt system. It is the simplest routine going, and a great fit for a first spa. Ask us which path fits the model you are considering.

Two friends laughing in a Caldera Utopia Geneva spa at dusk

See the Difference in Person

Burlington · Ferndale · Lake Stevens

The softness of salt water is easier to feel than to describe. Every showroom keeps salt-cared spas warm and filled, so you can put your hand in the water, see the routine up close, and get every question answered before you decide.

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Ready to get started?

Get real numbers on the models you’re weighing, or come sit in a few at one of our three showrooms. It’s the fastest way to know.