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Saltwater Hot Tubs – Myths & How They Actually Work?

For a few years now, salt has been all the rage in the swimming pool and spa world. If you are looking to install a new pool or buy a hot tub, you have probably heard of and want a saltwater hot tub.

But what does this mean? How does salt work? And is salt really the best option for keeping your water clean and clear?

The Big Salt Myth…

In my nearly 20 years in this industry, I have yet to see any product in such high demand yet so wildly misunderstood.

With that said, I want to get the biggest misconception about saltwater hot tubs out of the way as quickly as possible….when you ask for a saltwater pool or spa, you ARE asking for a chlorine pool or spa.

That’s because these systems are actually called Salt Water CHLORINE generators. You see, salt systems use salt to make chlorine. The salt is NOT what is doing the sanitation.

I think this is an important distinction because most customers who ask for salt are looking for a chemical-free, natural water care system, and that is not the way a saltwater hot tub is.

Now, if you have read this far, this article is really starting to sound like a hit piece on salt water systems, so I should state I actually think salt chlorine generators do a pretty good job of sanitizing water. The key thing to understand is that it is no different than having a slow drip-feed of bleach being pumped into your hot tub.

woman in a salt water hot tub

And just so you know, I am not biased. I have sold salt water chlorine generators to hundreds of customers in Massachusetts and New Hampshire.

The problem is the marketing for saltwater pools, and hot tubs have been very misleading over the years, so I always give my customers this same pitch about salt systems and let them choose what is right for them. For some people, salt is not the right solution for sanitizing their hot tub water.

In fact, if you are looking for a low chlorine hot tub, salt is NOT the right option. There are other systems out there that have been around for a lot longer than salt generators that actually use LESS chlorine than saltwater models.

Systems like ozone generators, UV light, and mineral systems which have been around for decades offer clean water solutions that are very low chlorine and low maintenance.

How Do Salt Water Hot Tubs Actually Work?

So now that we know salt water spas just use salt to create chlorine, we should know how they actually do that.

nacl gitter

The chemical compound for salt is NaCl known as Sodium Chloride. The basic idea is if we can separate Sodium from Chloride we can produce chlorine. That chlorine then mixes with the water just like it would if you poured in liquid bleach (also known as Sodium Hypochloride) into the hot tub. That chlorine will create a residual level in the water which can be used to sanitize and oxidize harmful contaminants.

So how does a salt chlorine generator separate the chloride from the sodium?

It uses a process called electrolysis.

Let us see the Wikipedia Explanation:

Saltwater chlorination is a process that uses dissolved salt (2,500–6,000 ppm) as a store for the chlorination system.[1] The chlorine generator (also known as salt cell, salt generator, salt chlorinator, or SWG) uses electrolysis in the presence of dissolved salt (NaCl) to produce chlorine gas (Cl2) or its dissolved forms -hypochlorous acid (HClO) / sodium hypochlorite (NaClO)- which is the sanitizing agent already commonly used in swimming pools. Hydrogen is produced as a byproduct too.

As such, a saltwater pool is not actually chlorine-free; it simply utilizes added salt and a chlorine generator instead of the direct addition of chlorine.

In chemistry and manufacturing, electrolysis is a technique that uses a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction.

Basically, it zaps the salt with electricity which causes the sodium and chloride molecules to separate.

Are Saltwater Hot Tubs Maintenance Free?

Umm… no.

Unfortunately, there is no system on earth that will eliminate routine maintenance of pool or spa water.  The good news is whether you have a saltwater hot tub or use any other kind of sanitation system, you shouldn’t spend any more than 5 minutes a week maintaining your hot tub water.

The only thing that is different in a saltwater chlorine generator hot tub (see what I did there <<<)  from a standard chlorine hot tub, is you do not add your chlorine manually.

All the other water balance chemicals are the same, you still have to test and adjust; PH, Alkalinity, and Calcium hardness.

salt water hot tub supplies

And truth be told, with the sensitivity of the expensive electrolytic cells used in the chlorine generators, water balance is even more important in a saltwater hot tub.

Again water care in a hot tub is fairly simple once you get into a routine, and your local dealer where you buy your hot tub will be there to help you every step of the way. So none of the above should scare you away from enjoying the amazing health benefits of hot water hydrotherapy.

There is some other maintenance involved in a saltwater hot tub as well. You do have to clean the cells periodically and or change the cells periodically, and those cells are not cheap. You can spend hundreds of dollars a year on salt cells.

What Are Some Low Chlorine Alternatives To Salt Water Hot Tubs?

There are 3 systems that can be found in many top hot tubs manufactured and sold in the US that have been used for years. I mentioned them earlier in the article.

Ozone Generators– Uses oxygen to create O3 gas, O3 is a strong oxidizer that will kill any bacteria or contaminates it comes in contact with, then it turns back into Oxygen – talk about natural!

UV Sanitation – UV rays are great at disinfection. UV actually scrambles the DNA of micro-organisms which prevents them from replicating and spreading to bathers in the water.

Mineral Sanitation – minerals like silver and zinc have been used since the days of the Roman Empire to sanitize bathing water.  The minerals wipe out contaminants on contact.

All of these systems reduce the demand for chlorine in your hot tub, combine them and you have a virtually chlorine-free sanitation system.

The spas we sell at St. Cyr’s Pool & Spa in Middleton MA use both ozone and mineral sanitation to reduce chlorine levels.  With a saltwater hot tub, your chlorine levels will be between 3 and 5 parts per million. With an ozone and mineral system, your chlorine levels can be between .5 and 1.5 parts per million! That is a drastic reduction in the amount of chlorine you are bathing in.

Should You Buy a Saltwater Hot Tub?

Saltwater chlorine generators do a great job of producing a consistent level of chlorine into your hot tub over time, and it can be a great system. Just realize there are plenty of other ways to easily add chlorine into your hot tub and keep it clean and clear with ease.

Just like ozone, UV, Mineral, Peroxide, and other sanitation options, salt is just one way to do it. The important thing when choosing a hot tub is finding one that fits your family, your body, and your lifestyle. Then the MOST important thing to consider is buying from a local dealer you can trust to support you for the life of your spa.

Hopefully, this article has been informative and has given you a good background of what a saltwater hot tub actually is, what it isn’t, and how it works.

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