Jacuzzi Hot Tubs in St. Louis

"Set and forget" is the phrase that sells more salt systems than any other. It is also the most misleading.

What the phrase actually describes is automated chlorine generation: the salt cell makes chlorine instead of you pouring it from a bottle. That part is real. Everything else about a salt system still requires your attention: pH balancing, alkalinity management, calcium treatment, phosphate treatment, non-chlorine shock, cell cleaning, filter cleaning, and adjusting the output level when usage changes or when you travel.

In fact, salt systems require more ongoing adjustment than other approaches. The electrolysis process constantly drives pH upward, so pH often needs attention every 3-4 days, not an easy once-a-week test with occasional tweaks. The acceptable balance ranges are narrower. The consequences of neglect are more expensive (corrosion, cell failure, over-chlorination). There is nothing "set and forget" about that routine.

No. A typical salt water hot tub or pool uses a salt chlorine generator. Dissolved salt (sodium chloride) is converted into chlorine sanitizer inside the water. The chlorine is made on-site instead of poured from a bottle or tablet. Salt is the feedstock; chlorine is still the sanitizer.

Calling that setup chlorine-free is one of the most common myths in water care, including in search and AI answers when the question is vague. When the question is asked this directly, the correct answer is simple: salt water systems still use chlorine.

Softer-feeling water is one of the things salt water hot tub sellers mention. But what is actually happening is the sodium chloride is dissolving your skin's outer barrier. During the soak that feels "silky or slippery." When you get out, salt residue stays on the skin and keeps pulling moisture out through the same barrier damage, so skin often turns tight and itchy as it dries. For anyone with sensitive skin, it can be much worse.

Our salt water customers tell us they often end up showering and applying lotion after every soak. That extra step is one of the top reasons people stop using their hot tub as much as they expected. Others drop salt and switch to approaches that feel soft without the drying aftermath.

The word "salt" sounds natural, so it is easy to believe you are getting away from chemicals. But "salt" is a chemical: sodium chloride, NaCl. The same molecule in table salt and road salt. And the system generates chlorine (hypochlorous acid) inside the water, the exact same sanitizer that comes from chlorine granules or tablets. No chemicals were removed; they were just moved from a bottle to a generator.

What changes is the list of extra steps. A salt system requires pH balancers (more than other systems because electrolysis constantly pushes pH upward), alkalinity increaser, calcium treatments, phosphate treatments, non-chlorine shock, and cell cleaner. You are not using fewer chemicals; you are swapping one set for a more complex one.

There is another hidden limitation. Salt systems are generally incompatible with ozone and UV devices because salt and the electrolysis process are corrosive and will destroy that equipment. Ozone and UV can cut chlorine demand on a non-salt tub from about 3-5 ppm down to roughly 1 ppm. Block that path and you stay locked into higher chlorine with no way to lower it that way.

When brands explain the incompatibility, the wording is often careful in two ways. First, they may call the output "sanitizer" instead of chlorine. Second, they may say ozone "counteracts sanitizer production." Chlorine and ozone have been used together successfully in hot tub water care for decades. The problem they avoid naming is corrosion: salt plus electrolysis is hard on components. In practice, some salt installs require removing factory ozone (for example, Hot Spring spas that ship with ozone may have the dealer remove it when a salt system goes on). If ozone stayed in place, owners would see how fast that device fails, which is a visible hint of the same corrosive environment acting on the rest of the spa.

If you smell "chlorine" coming from any body of water (a pool, a hot tub, a salt water system), it means something is wrong. That sharp odor is not chlorine. It is chloramines, a byproduct formed when chlorine has already reacted with sweat, body oils, or other organic matter. The chlorine did its job and is now spent. The smell is a signal that byproducts are building up.

This chemistry is the same in salt water and non-salt systems. Both use chlorine; both can form chloramines when organic load exceeds what the system can handle. A salt system can mask the issue temporarily by producing chlorine steadily, but when the tub gets heavy use or maintenance slips, the smell returns, because the underlying chemistry has not changed.

The real fix is not switching how you deliver chlorine and taking on all the consequences that come with a salt system. It is running lower chlorine with supplemental water treatment, so there is less chlorine available to form chloramines in the first place.

Salt water hot tubs are often sold as better for people who travel, because the system continues generating chlorine while you are gone. That is exactly backwards. The system keeps making chlorine regardless of whether anyone is using the tub. If you do not turn the output down before you leave, the chlorine will build up to extreme levels. You will come home to water that smells like bleach, irritates your skin and eyes, and often needs to be drained completely.

This is the most common complaint we hear from salt water owners: "I forgot to turn down the system before I left town."

A salt system requires a specific pre-travel routine: shock to 3-5 ppm, clean the filters, lower the output setting, and secure the cover. Miss any step and you have problems. The system's own safety net (a default low-output mode) does not kick in until day 15. Most trips are shorter than that.

A salt water pool and a salt water hot tub use the same technology (a salt chlorine generator), but the experience is completely different.

Temperature. A pool is roughly 85°F. A hot tub is about 104°F. A peer-reviewed study found that hot water (106°F) damages the skin barrier roughly 3.5 times more than cold water, measured by transepidermal water loss. Hot water opens pores, strips natural oils, and compromises the skin barrier before the salt even has a chance to act.

Humidity. Salt pulls moisture from wherever it can. Its threshold is roughly 76% relative humidity. Below that, it draws from your skin. Above that, it draws from the air. In St. Louis summer, outdoor humidity regularly exceeds 76%, so the salt on a pool swimmer's skin often pulls from the air. A hot tub is used year round, especially in cooler months when humidity here is far below 76%. The salt has nowhere to pull from except your skin.

The type of salt. Salt water pools and hot tubs use sodium chloride, plain table salt. The same chemical as road salt. Not Epsom salt (magnesium sulfate), not Dead Sea minerals, not a therapeutic mineral bath. The word "salt" covers completely different chemicals with completely different effects on skin.

The combination is what masks it. The same sodium chloride is present in both systems. The same mechanism is at work. The difference is that the cool water and high humidity of a pool environment prevent the swimmer from experiencing the discomfort that a hot tub owner feels directly. The salt will always dry something; the conditions determine whether it is the air or your skin.