Salt Water Hot Tubs: Here’s What You Need To Know In 2020



There’s something magical about a salt water hot tub. Not only can you recreate the luxury of a high-ticket spa in your home, but you also have a host of benefits for soaking in the relaxing salty waters.

But converting your existing system requires more than simply dumping a bunch of table salt into the water, and it’s not a decision to make lightly.

In this article, I’ll help you to understand the mechanics of the salt water chlorination process, alongside everything you need to make the conversion a success.

What Is A Salt Water Hot Tub?

Well, it’s pretty much what it sounds like, a hot tub that’s been filled with salt water.

Using a device called a chlorinator, the salt water is transformed into a sanitizing agent for your hot tub. Compared to the traditional bromine or chlorine solutions for fighting algae and bacteria, a saltwater system is an eco-friendlier option.

Many people actually prefer salt water systems for their hot tubs because it’s gentler on their skin, easier to maintain month to month, and is also more cost-effective to run.

How Does It Actually Work?

Using salt in your hot tub seems a little weird until you remember its actual chemical name, sodium chloride. All you’re doing is releasing this particular molecule into the water.

With the help of a tiny, tiny, bit of electricity (no, it won’t shock you), the chloride molecules from all the salt in your hot tub are set free so they can start sanitizing the water.

As I said above, this process happens inside a device called a salt water chlorinator which is a crucial piece of equipment if you’re planning to have a salt water hot tub.

But when I say “salt water”, this isn’t salty like at the beach. Far from it. All you really need for this process to work is to get your salinity levels to 2,500 PPM, which in real terms is approximately 2 pounds of pool salt for every 100 gallons.

That’s not even enough to taste in the water. Of course, not that you should actually be drinking the water from your hot tub. That’d be weird.

What Are The Benefits?

Natural and cost-effective sanitizer

When you’re using a salt water hot tub, you won’t need to add chemicals like bromine or chlorine to keep it sanitary. Salt is a natural product, which makes it a more environmentally friendly solution.

Now pool salt is what’s typically used, and in addition to being a natural sanitation solution, it’s also more cost-effective than traditional pool chemicals.

Gentle on your eyes and skin

The chlorine that’s been generated from the salt water solution will actually make the water in your hot tub “softer,” which has two key benefits.

It’s less irritating to your eyes and skin than traditional pool chlorine, and the active oxygen molecules in the water are almost a mini skin treatment session, leaving you feeling refreshed and rejuvenated.

No lingering chlorine smells

If you’re not a particular fan of that bleachy “chlorine” smell that comes with running a pool or a hot tub, converting it to a salt water system will eliminate this for good.

Because of the way the chlorinator works in the water, there are no harmful chloramines produced (i.e., what you’re smelling when you notice that odor).

Ongoing maintenance gets easier

Of course, no particular system is maintenance free, but running a salt water chlorinator is far less work than any other option you’ve got for your hot tub. Designed to self-regulate, all you need to do is top up the salt when it gets low. Some chlorinators even use a reverse-polarity design to stop the build-up of scale inside your hot tub and all the internal systems.

What Are The Drawbacks/Misconceptions?

The initial investment required

Despite the lower on-going costs, the initial installation of a saltwater hot tub system is quite a bit more than what you’d pay for a traditional filter. The good news, the system will last for more than a few years, though I do want to make it clear certain parts, like the saltwater cell, will need to be replaced every few years. It’s important to budget accordingly.

It can void the manufacturer’s warranty

Be very careful to read and understand the fine print of your hot tubs warranty before converting to a salt water system, and confirm there are no problems before you set it up. In some cases, specific systems can void the warranty from the hot tub manufacturer, which you need to be well aware of before you start the conversion.

You may still need to shock

While the maintenance of a salt water hot tub is far less than what’s required with a bromine or chlorine system, it doesn’t mean you can neglect your hot tub entirely. It’s essential to consistently monitor the water quality, and understand that if things do get out of balance, a “shock” may be required to get the water clean again.

Temperature levels are key

As the temperature levels drop, the actual effectiveness of your saltwater system to produce chlorine goes right down. Under 60 degrees Fahrenheit will create problems for the system, as most shut down at these temperatures or below, which can create a breeding ground for micro-organisms as the chlorine levels plummet.

How to Convert to a Salt Water System

Now, converting your hot tub to a salt water system is relatively straightforward, there are several steps in the process.

The easiest option is a drop-in chlorinator, but if you prefer you could always choose an in-line generator, which will require professional installation.

1. Empty, clean and refill your hot tub

The first step is to drain all of the water so you can start fresh with the new saltwater system. It’s also an excellent time to give your hot tub a good clean out, flushing all of the lines and using a proper cleaning solution while you’ve got it nice and empty.

It goes without saying to give it a good rinse when you’re done, then refill it with clean, filtered water.

2. Test the levels and add your salt

Before adding any salt to the water, I like to check the chemistry. So, you can see the effects of not only the salt but what this has on particular balances like the pH, alkalinity and calcium hardness in the water.

It also ensures you’re putting the right amount of salt in, but what’s most important here is to follow the product instructions.

3. Retest and confirm the levels

Next step is to confirm there have been no significant changes in your water chemistry after adding the salt, and now is the perfect time to ensure the right balance exists in your pool (at least at these early stages).

It’s also essential to confirm that the pH, alkalinity, and calcium levels are all within safe ranges, right from the get-go. Otherwise, adjust as needed.

4. Installing the salt water system

What’s critical is that the cables on your chlorinator reach the GFCI (ground-fault circuit interrupter) outlet you have alongside your hot tub and that the wires are long enough to get the chlorinator cell into the water.

Put all this in place, but don’t plug it into the outlet yet. What I want you to do now is to mount the control panel to a nearby post, so it’s secure.

5. Get the cell in the water

Following the instructions of the particular chlorinator, you’ve bought, set the device up in the water.

Read the instructions carefully and follow them to the letter. Get it wrong, and the system won’t work. Oh, and try and get the cell as deep as possible in the water, this helps it to distribute the chlorine more evenly throughout your water.

6. Plug it in and start it up

This step is pretty self-explanatory, but here goes. Plug the chlorinator in, and turn it on.

There may be a particular program you need to set on your specific device, again, your best course of action here is to follow the instructions provided by the manufacturer.

7. Retest the salt levels and enjoy

Once it’s been running for at least 24 hours, check and retest the salt levels to ensure it’s all within safe levels for you to start using the hot tub.

If any adjustments are needed, do the necessary, otherwise, slide in, sit back, and enjoy relaxing in your new salt water hot tub.


Converting a hot tub into a saltwater system isn’t an overly complicated process, but there are a few key considerations to make before you go all-in on the switch.

The trick is to understand all these, weigh up the different costs and advantages, then make the right choice for your family.

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In this article, we'll help you to understand the mechanics of the salt water chlorination process, alongside everything you need to make the conversion a success.  #poolonomics #hottub #spa

Categories: Hot Tub Care, Hot Tub Construction