Subscribe

Subscribe

To get exclusive hot tub deals, discounts, and advice

How to Convert Your Hot Tub to Saltwater – A Step-By-Step Guide

An engineer’s approach on converting your hot tub to saltwater – Check our 5-step guide on how to do it easily and ditch chemicals

If you decide to convert your hot tub to a saltwater tub, you’re aware of its benefits that include freshness, softness, easy maintenance, and fewer chemicals.

And you may have the following questions that we will answer in this article. 

  1. Can any (my) hot tub be converted to a saltwater tub?
  2. What is better saltwater: Chlorinator or Brominator?
  3. What is better: Drop-in or In-line saltwater system?
  4. What do you need for conversion to a saltwater hot tub?
  5. How to install a saltwater system?
  6. How to maintain a saltwater hot tub?
  7. Are saltwater hot tubs more expensive compared to Chlorine/Bromine tablets?

The main question — is it possible to turn any hot tub into a saltwater tub? 
In a nutshell – yes! Let’s see how it works to understand why and how.

Using a natural chemical reaction between salt and water — electrolysis, saltwater systems provide your hot tub with a steady supply of chlorine or bromine. These are the same sanitizers that are commonly used for hot tub water, but with the saltwater system, they are produced naturally. 

You don’t need to add salt daily. Only on the initial setup. The salt system generates chlorine/bromine after it breaks down back into salt and the cycle continues since salt does not evaporate from the water. You may need to add extra salt only if you add a lot of new water. Otherwise, the system uses the same salt till the next refill (up to a year depending on the intensity of usage). This makes the installation of this system more attractive — continuous savings on chemicals.

Saltwater system operation diagram (using a chlorine generator as an example)
Source: Pinterest.com

Verdictevery hot tub can be converted to saltwater because saltwater systems generate the same sanitizers used in hot tubs. Slightly salty water will not damage your equipment, although you should ensure that the salinity is within the normal range (2000-2500 ppm). It’s easy to control the salinity with Salinity Test Strips.

Important — check with the spa manufacturer to determine if this conversion will void your warranty.

5 steps to convert to a salt water hot tub

Now, we will follow a step by step guide that covers the whole process of conversion to a saltwater hot tub.

Step 1 — Decide how to convert to a saltwater tub — Chlorine vs Bromine 

There are two ways to get a saltwater hot tub — chlorine generators and bromine generators. Chlorinators are more popular as they are at least half the price of brominators (often people don’t even know that there are brominators). There are also saltwater systems that can produce both — chlorine or bromine depending on the type of salt you use (always read manuals and make sure the salt is suitable for your device).

Chlorinator Brominator
(use Sodium Chloride to produce chlorine)(use Sodium Bromide to produce bromine)
Price range $
Price range $$
Chlorine is both an oxidizer and a sanitizer. Additional shocking may be required only after very intensive useBromine is only a sanitizer. Additional shocking may be required more often than with сhlorine
Chlorine is less effective than bromine at temperatures above 75°FBromine works better than chlorine at higher temperatures (above 75°F)
Chlorine is less effective than bromine at varying pH levels. Less efficient loss of bromine at varying pH levels (compared to chlorine).

Saltron Mini Salt System

Price range: $

Drop-in chlorinator
No plumbing required
Durable titanium cell


ControlOMatic SmarterSpa

Price range: $$

Drop-in chlorinator
No plumbing required
Durable titanium cell
Self-cleaning technology

Bromine Generator BluWater

Price range: $$

Free of chlorine
Easy to install
Economically and environmentally friendly

Note: Only bromine generators should be used in wooden hot tubs because chlorine has a bad effect on wood.

Verdict: 

I can’t give a simple answer to which is better, bromine or chlorine? This age-old dilemma also applies to saltwater systems. Сhoose what is more suitable for you based on the characteristics. 

Chlorinator — is my personal choice for saltwater hot tubs since it has significant advantages: the cost and the availability of the device and the cost of salt. 

Tip: If you are still hesitant, buy a salt system in which you can use both salts and try it by yourself — you can use the ControlOMatic SmarterSpa.

Step 2 — Decide which device you use to convert —Drop-in or In-line

There are two types of saltwater system constructions — Drop-in and In-line. Here, I’ll give you an overview of each design and its pros and cons.

  • Drop-in saltwater generators — you only need to submerge the cell into the hot tub water to make it work.
Drop-in Saltron Mini Salt System construction 
Source: Spadepot.com

Construction is very simple and consists of 2 main parts: 

Control panel — a control unit for adjusting the intensity and amount of chlorine or bromine extraction, a timer, and other functions depending on the model.

Electrolytic cell — produces chlorine/bromine, consists of a plastic case containing electrodes. They are usually made of Titanium (corrosion-resistant material).

Some models (e.g. Saltron Mini) are equipped with a cell holder, which is very convenient and used to place the cell in (according to safety rules you should remove the cell from the water while soaking in the hot tub)

Pros: price, easy installation

Cons: visible cables

Saltron Mini Salt System Drop-In Saltwater Chlorine Generator
ControlOMatic SmarterSpa Saltwater Smart Chlorine Generation System
  • In-line saltwater generators — it works on the same principle but the сell is installed by attaching it directly to the hot tub’s plumbing.
In-line Hayward AquaRite Salt Chlorination System construction
Source: pinterest.com

Construction consists of 2 main parts: 

Control panel — a control unit for adjusting the intensity and amount of chlorine or bromine extraction, setting the timer and other functions depending on the model.

Electrolytic сell — produces chlorine/bromine, installed in the pipe of the hot tub. Thus, it is hidden and does not cause inconvenience.

These types of salt chlorinators require more work to install, and you’ll likely need to hire a professional to help. Commonly designed for big pools from 15,000 gallons and above, but this should work for most hot tubs too.

Pros: no visible wires

Cons: price, tricky installation

BLUE WORKS Pool Chlorine Generator Chlorinator
Hayward W3AQR3 AquaRite Electronic Salt Chlorination System for In-Ground Pools
BLUE WORKS Salt Water Pool Chlorine Generator System

Verdict: 

The drop-in saltwater systems are the best choice for hot tubs, as in-line ones are designed mostly for pools with a large volume of water, require professional installation, and are up to several times more expensive. But, you can still use them if you don’t want extra cables in your spa. 

Step 3 — Buy everything you need for conversion to a saltwater hot tub

I made a list of what you need to buy before starting. You should check it as you may already have some of the things and will save on spending. 

  • Saltwater system
    Buy a saltwater system after deciding which device suits your needs
Saltron Mini Salt System Drop-In Saltwater Chlorine Generator
ControlOMatic SmarterSpa Saltwater Smart Chlorine Generation System
Hayward AquaRite Electronic Salt Chlorination System
  • Salt
    Use only a specified high purity pool salt (NaCl, NaBr)
    Tip: consider adding 75 percent of the recommended amount of salt and then testing the water. Remember, lowering the salinity of a pool is a lot harder than raising it. 

Step 4 — Prepare the hot tub for conversion to a salt water tub

Now you need to prepare the spa for the saltwater system installation. For the system to work properly, you need to start it with fresh, clean water. Contamination and residues of hot tub sanitizers will interfere with the operation of the saltwater system.

1.Clean and drain a hot tub 

Clean the hot tub with a hot tub cleaner before draining to remove contaminants from inside of the spa plumbing and jets. Drain the water and clean the surface.

2.Refill the hot tub

Refill the hot tub as usual but use a hose with a filter to ensure maximum water purity.

3.Check hot tub water chemistry

saltwater systems require balanced and pure water to start and work correctly. Check the water with test strips and balance the water if needed (jump to the section to see how).

Step 5 — Install the saltwater system

Installation instructions for each type of saltwater system

The drop-in saltwater system is the best choice for hot tubs because of affordable price, easy maintenance, and easy installation:

  1. Mount the control panel and cell holder (if provided) on the spa wall or near the spa. Choose a location that will protect from rain, moisture, and direct sunlight.
  2. Add salt — the amount of salt to add depends on the size of the spa. Add salt to warm water, it will help dissolve the salt faster.
  3. Dip the cell in the water — it should hang vertically in the deepest location of the hot tub, it’s not recommended to place the cell in the filter area.

Installation is complete and now you can plug it in and turn on the saltwater generator.

Starting a saltwater system
Source: solaxx.com

In-line saltwater generators require difficult installation. The cell should be installed in the spa plumbing after the filter and heater. This way, the water will flow through the cell in the correct direction and concentrated chlorine will not pass through any other equipment and will not damage it. We recommend that it be done by professionals per the manufacturer’s instructions. 

Congrats! Now you have a saltwater hot tub. Enjoy fresh and soft water with minimum chemicals.

How to maintain a saltwater hot tub. You still need chemicals

  • Chemicals — saltwater hot tubs also need chemicals, besides chlorine\bromine which are produced naturally. It is very important to note that this is just one component of your spa water chemistry. 
    Test your hot tub water chemistry with Test Strips for Spas and Hot Tubs and maintain recommended levels (as shown in the table below) with hot tub chemicals. It’s easy to get all the chemicals you need for a saltwater hot tub in one kit — Hot Tub Chemical Balancer Maintenance Kit.

The table shows the optimal water chemistry for hot tub spas which you should maintain. Check it with 

Parameter Recommended Level
Salt2000 to 2500 ppm
Free Chlorine2.0 to 3.0
pH7.2 to 7.6
Total Alkalinity80 to 120 PPM
Calcium Hardness200 to 400 PPM
Cyanuric acid (stabilizer, used in outdoor spas only)50 to 80 ppm
  • Shock — saltwater hot tubs also need to be shocked weekly, after intensive use or if you haven’t used it for a long time. You should also shock the hot tub if your water chemistry levels are good, but the water is cloudy or smells. You can use chlorine shock or non-chlorine shock for saltwater hot tubs (depending on what salt you use).
  • Cell inspection — the cell should be inspected every 3 months. Unplug the system and inspect the cell for a scaling white deposit. If it exists, you should clean the cell with vinegar or muriatic acid (see the manufacturer’s instructions). 

Is a saltwater hot tub more expensive versus chlorine/ bromine tablets?

The initial cost of a saltwater hot tub is higher because you need to buy the saltwater system and change the cell every 1-5 years (depending on the model). However, in the long term, the cost of a saltwater hot tub will be less than using chlorine/bromine tablets which you should add every week. 

So, you won’t pay more, and you will get a lot of benefits:

  • Improved water quality – the salt used with a generator provides continued skin softening, no skin or eye irritation, and no harsh chemicals on your swimsuits.
  • Reduced maintenance – you don’t have to remember to add chlorine every week. You don’t have to store and contact it.
  • Environment friendly – saves water (refill it once a year), less chemical usage (add salt once instead of weekly adding of chlorine/bromine), no need to recycle packaging, and pollute the environment when manufacturing chemicals.

FAQ

💡How do salt water hot tub systems work?

The saltwater generators rely on electrolysis. As a result, you have a system that naturally produces chlorine or bromine from salt. Then it is circulated into the water to sanitize and disinfect it.

❓Can any hot tub be converted to saltwater?

What is the best robotic pool cleaner to buy? Dolphin Nautilus CC Plus — Good cleaning at an affordable price Polaris Sport Robotic F9550 — Convenience with added benefits Yes, every hot tub could be turned to saltwater, even inflatable and wooden tubs (with restrictions which we described in the article). Slightly salty water is suitable for any hot tub surface and equipment.

❓Can wooden hot tubs be converted to saltwater?

Yes, but with restrictions. In wooden hot tubs, bromine generators should only be used because chlorine has a bad effect on wood.

💰Are salt water hot tubs more expensive?

The Initial cost of a saltwater hot tub is always higher because it requires saltwater chlorine or bromine generators. But, the maintenance is cheaper than the maintenance of a traditional hot tub. You don’t need to add chlorine or bromine regularly. You need to add salt when you fill the hot tub with water and the system utilizes this until the water is replaced (from 3 months up to 1 year depending on the intensity of usage).

🧂How salty will the hot tub water be? Like seawater?

You won’t taste salt or see it on the walls and skin. Just compare seawater — 35,000 ppm, human tears — 9,000 ppm, hot tub saltwater — 2,500 ppm.

⚖️How much salt do I put in my saltwater hot tub?

The amount of salt depends on the volume of the spa and is about 2 pounds for every 100 gallons, you should achieve an optimal salinity of 2000-2500 ppm.

📅How often do you have to add salt to the saltwater hot tub?

You do not add salt daily. Only on the initial setup. The salt makes chlorine/bromine, and the chlorine/bromine breaks down back into salt. Again, you may need to add salt if you add a lot of new water.

Related Posts

Do NOT follow this link or you will be banned from the site!