Every hot tub showroom in BC will tell you saltwater is gentler, easier and better for your skin. Some of that is true. But the sentence that gets left out of the pitch is the one that matters most: a saltwater hot tub is a chlorine hot tub. It just manufactures the chlorine itself instead of asking you to pour it in.
Once you know that, the comparison gets a lot more honest. Here is what actually separates the three common approaches.
How Each System Actually Works
| System | What sanitises the water | What you handle |
|---|---|---|
| Traditional chlorine | Chlorine you add | Dosing sanitiser regularly, testing, balancing |
| Saltwater | Chlorine generated from salt | Adding salt periodically, replacing the cell, still testing |
| Ozone (Ecozone) | Activated oxygen, plus a small sanitiser residual | A short monthly routine |
A salt cell works by electrolysis. Current passes through salted water and converts dissolved salt into chlorine right there in the plumbing. It is genuinely more convenient than hauling jugs, and the chlorine level tends to be steadier because it is produced continuously rather than in a spike every time you dose.
Ozone is a different mechanism entirely. Instead of holding a chemical residual in the water to kill things slowly, ozone oxidises contaminants on contact and then reverts to ordinary oxygen. It acts roughly 3,000 times faster than chlorine, and because it breaks back down, it does not accumulate. The Ecozone system does the bulk of the sanitising so the residual chemical load stays low.
The Skin Comfort Question
Saltwater does generally feel softer, and that is a real benefit if chlorine bothers you. But the reason is not the salt. It is that a well-tuned salt system holds a lower, steadier chlorine level than a tub that gets manually dosed in bursts. A low, stable sanitiser level is what your skin is responding to. Any system that achieves that gives you the same comfort, which is why an ozone-primary tub reads the same way to most people.
What Salt Does to the Rest of the Tub
This is the part worth thinking hardest about. Salt water is corrosive, and it is in contact with every wetted component for the life of the tub. In a conventional spa that means the heater element, the jet hardware, the fasteners and any exposed metal trim. Manufacturers design around it, but "designed around it" is not the same as "unaffected by it."
It also interacts with the shell. An acrylic shell is a layered assembly, acrylic bonded to a fibreglass backing, and any pathway that lets water sit against the substrate is a place where problems start. A one-piece HDPE shell has no seams, no bond line and no substrate to reach, which removes that pathway entirely. It is also chemically inert, which is exactly why HDPE is the material used for industrial chemical storage tanks.
Running Cost, Honestly
Salt systems are often sold on savings. In practice, the sanitiser line item on a hot tub is small no matter which route you take, and salt cells are a consumable. When a cell reaches the end of its service life you replace it, and that is not a trivial part.
The costs that actually move the needle over ten years of ownership are electricity and the cover. In BC, a well-insulated tub runs roughly $10 to $40 per month in power depending on season and whether you are on 110V or 220V. A poorly insulated tub with a waterlogged foam cover runs closer to $25 to $75. And a foam cover typically needs replacing every three to six years at around $800 a time. Those two lines dwarf anything you will ever spend on sanitiser.
Which Should You Choose?
If you already own an acrylic spa and hate handling chemicals, a salt system is a reasonable upgrade and you will probably like it. If you are choosing a new tub, do not let the sanitiser decide it. Pick the shell, the cover and the insulation first, because those determine what the tub costs to own and how long it lasts. The water care sits on top of that decision, not underneath it.
For what it is worth: every Eco Spa can run Ecozone as an upgrade, and the maintenance routine is a personal template our team builds with you at delivery rather than a generic dosing chart. Visit a BC showroom and see the water for yourself, or request a quote.
Frequently Asked Questions
Do saltwater hot tubs still use chlorine?
Yes. A saltwater system is a chlorine system. The salt cell runs an electrical current through salty water and splits it into chlorine on demand. You are not swapping chlorine for salt, you are changing where the chlorine comes from. What changes is the handling: you add salt a few times a year instead of dosing sanitiser weekly.
Is a saltwater hot tub cheaper to run?
Not usually. You buy less bottled sanitiser, but salt cells are a wear part that needs replacing on a schedule, and the cell is not cheap. Over a full ownership window the two approaches land close to each other. The bigger cost difference in a hot tub is the cover and the shell, not the sanitiser.
What does ozone do that salt and chlorine do not?
Ozone is activated oxygen. It oxidises contaminants on contact and then reverts to ordinary oxygen, leaving no residue to build up in the water. Eco Spa uses ozone through the Ecozone system so the sanitiser is doing far less work, which is why the maintenance routine drops to a few minutes a month.