7 Steps to Convert Your Hot Tub to Salt Water

Whether you want to enjoy fresh seawater at home or simply reap the many benefits of saltwater, converting your hot tub to saltwater is a practical choice. Here’s how you can go about this project.

The steps to convert your hot tub to salt water are draining and refilling it with clean water, stabilizing it chemically, and attaching a salt water chlorinator on a pre-marked spot. Alternatively, you can refill the tub with clean water and drop a drop-in saltwater generator to get the job done.

In this article, you’ll learn about each step, including how to:

  • Get rid of tub water
  • Mark the pipe where the salt water generator must go
  • Refill water and add chemicals
  • Attach inline salt water generator or drop in a drop-in chlorinator
  • Turn on the chlorinator

Salt Water Hot Tub Conversion: A Brief Overview

There are two ways to convert your tub to saltwater. The more straightforward among the two is simply dropping in, a drop-in saltwater chlorinator. What is a saltwater chlorinator, though? It is a device that you can place in the middle of your hot tub or fix by an interior side. Once you plug it into the electric outlet, you will have free saltwater in your hot tub.

The problem with such a contraption is that it is not as safe as an inline salt water chlorinator. That’s because there’s an electric wire hanging within your pool when you use a drop-in chlorinator. Needless to say, it is not as aesthetic or safe. Safety is the senior concern because even if you find a way to hide the wire, it could get exposed due to various reasons and pose an electrocution hazard.

However, if you do not have any children or pets, it can be a practical solution to generate saltwater without having to take apart your hot tub’s plumbing. With that out of the way, the safer way to convert your hot tub to salt water is to turn it into a saltwater hot tub by installing a similar chlorinator into the plumbing of your hot tub. And for that, you have to take specific steps so that you do not end up with an oversalted or an under-chlorinated tub.

1. Drain Out the Water

Do not try to convert the current pool of water in your tub to salt water because it isn’t chemically controlled. The first step is to drain your hot tub. Just because you can drop in a chlorinator in a illed tub doesn’t mean that it is ideal for the conversion process.

This is especially true if you’re not going with a drop-in gadget. A pre-filled tub is at contamination risk when you’re switching to an inline chlorinator. The key reason behind draining the tub is not that you get to work with an empty tub only. It has more to do with having clean water you can chemically balance soon after filling.

The fewer impurities involved, the more control you have. Once your tub is converted to saltwater, you will not have to worry about impurities as much. So, minimize the unintentionally accumulated impurities like dust, dirt, and microbes to give your saltwater hot tub a fresh slate, especially if you have not modified a hot tub before.

Once you have drained your hot tub and are sure that there’s no water or any residue of chemicals contaminating the space, you are in a better position to start focusing exclusively on the plumbing and the chemical balance of the tub water.

2. Establish the Attachment Area

In the second step, you will mark where the chlorinator will be placed. You may think that you can start working with the plumbing since there’s no water in the hot tub. This is not the stage where you place the chlorinator. However, this is the stage where you can take a marker and mark where you will place the chlorinator.

When looking for a place to attach your saltwater chlorinator, you should consider open walls while keeping an eye out for places where there are joints in the plumbing. That’s because you do not want to saw open the pipe; that can be a last-resort alternative.

No hot tub is powered by a single long pipe. You’d ideally have points where smaller pipes are brought together with a joint after the filter pump. If that’s the case, the rest of the process becomes quite easy as you can take that apart and place a saltwater chlorinator, and you’re done.

Even if not every hot tub has a joint right after the heat pump or filter pump, it still helps to examine the plumbing. Doing it while your pool is because it is simpler. Take a marker and place an X mark where you will install the chlorinator. Most chlorinator packaging will include some instruction as to where this fits, but for the most part, you would want the saltwater chlorinator to be at the bottom so that the distribution is optimal.

You will also need it somewhere closer to where the water is being released back into the hot tub. It is inefficient to the saltwater chlorinator behind the filter. If you have a filter panel, make sure that the saltwater generator is in line at the other end of the filter, so only filtered water goes through the chlorinator. 

Also, make sure that the chlorination doesn’t happen before heating, and the water is at the other end of the heat pump when it is salted. If you follow these best practices, you will be marking your X closest to the water outlet that flows water into the tub after the filtration and the heating systems are done with it.

3. Refill the Tub With Clean Water

As the subheading suggests, this is the stage where you refill the hot tub, this time without any chemicals. Make sure that it is filtered and is as close to tap water as possible. Ideally, having a garden hose with a hose filter on and attaching it to a tap is the best way to fill your hot tub before you prime it for turning it to saltwater.

Fill the hot tub up to the required level depending on how big your tub is and how much water you want. Ensure that the drainage is off and the water isn’t circulating either. Double-check to see that the filtration and heating systems are off and not operating. The water must not be circulating through the pipes because they will need to be taken apart for the chlorinator to be installed.

4. Balance the Chemicals

Test the chemical composition and the salinity at this stage. Before you add salt to the water that you have accumulated in the hot tub, you have to test whether it is already naturally salty. You should also check whether the chemical composition, the pH, and purifying chemicals’ volume are exactly to the specifications of the saltwater chlorinator’s required levels.

Please recognize that this step is different for different readers as requirements change depending on the region that you are in because some regions’ water is naturally saltier than others, especially if your water supply is connected to a locally drilled water source. On the other hand, water supply serviced by a filtration facility or by a provider that does the filtration on their end will be pre-primed for saltwater.

It is also worth noting that the specific chlorinator will have certain instructions regarding this. Therefore, you can test the salinity of the water and the chemical levels using specific testing kits. Even though taste tests are not ideal, if you can taste the salt, it’s already too much. That should never be the case before you have dumped pool salt into the mix.

5. Add Pool Salt

This is the step where you have to add pool salt that matches in quantity with the amount of salt required by the specific chlorinator and the volume of water that your hot tub can hold. You can go with table salt for this, but because that salt is not as coarse as pool salt, it might take longer to get to those levels. 

Also, table salt is packaged and priced differently than pool salt, making it more expensive to get the same quantity of what is basically the same chemical composition. All in all, getting a bag of pool salt is much better.

A final word of caution on salt levels: make sure that the quantities that you drop match by ratio and not by quantity recommendations. Most pool salt packaging contains recommendations for an average pool. But you’re pouring that into a hot tub, so you have to adjust them, so it matches a smaller amount of water.

6. Mount / Install the Chlorinator

This step varies depending on whether you’re going with a drop-in chlorinator or an inline chlorinator. If you are opting for a drop-in chlorinator, you can simply install the control panel close by and then drop the chlorinator into the water. That’s it! Once again, just make sure it is in the deepest region so that distribution is proper throughout the hot tub. You don’t have to worry about the chlorinator being before or after the filter pump or the heat pump.

It is fairly easy to take care of, and you can simply pop the electric plug into the outlet and turn on the chlorinator. On the other hand, if you are going with an inline chlorinator, you will need to first take apart the pipe where you marked x in an earlier stage. Ideally, this would be around a spot where two pipes were joined with a joint, but if that’s not the case, you might need to saw open space in the pipes and attach the saltwater chlorinator where appropriate.

If you don’t have a joint to work with, having a local plumber help with this would be a good idea. It is recommended for this step because if you’re going with an inline chlorinator, getting a hot tub or a pool expert would be a more expensive approach with pretty much the same level of plumbing safety as a professional plumber.

However, when you’re working with the neighborhood plumber, make sure that he installs the chlorinator exactly where you marked the X and is not attaching it before the filter or the heat pump. It has to be as close to the end, which releases water into the hot tub, so there are no salt deposits inside the circulation plumbing.

7. Turn on the Saltwater Generator

Once you have installed the chlorinator, regardless of whether it is a drop-in or inline variety, you are ready to turn the system on and enjoy your saltwater hot tub. If it is a drop-in chlorinator, you simply need to turn it on from the attached panel. If it is installed inline, you just need to turn on the water circulation. Either way, you are now ready to enjoy the fruits of your work.

Final Thoughts

The great thing about saltwater hot tubs is that you don’t really need to build one from scratch. Simply draining your hot tub, filling it with clean water, and dropping in a drop-in saltwater generator after you have put sufficient pool salt in, is all it takes to convert your hot tub to saltwater.

Jed Arnold

Jed spent every year from the ages of 15 - 22 as a Lifeguard (Red Cross) and ages of 17 - 22 as a Certified Pool Operator (CPO). Between working for over a dozen facilities and owning a pool, he carries over a decade of pool experience.

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