The Ultimate Guide to Hot Spring Spas Freshwater Salt System Startup


Table of Contents

A common question we get is how do you start a FreshWater salt system? To help answer that question we created this guide. In this guide we will cover step by step how to start up and set up a Hot Spring Spas Freshwater Salt System.

The Freshwater Salt System is an option on Hot Spring Spas that converts salt into chlorine automatically. Once started up a hot tub owner will only need to maintain pH,  Alkalinity, and Calcium Hardness.

This conversion of salt into chlorine is made possible by the Hot Spring Spas Freshwater Salt Cartridge. These cartridges are amazing as they are maintenance free and only need to be replaced every four (4) months.

Please note the first two steps of the start up process, (1) Installing the Salt Cartridge and (2) Filling the Spa should be done with the power turned off to the spa.

Play Video about Freshwater Salt System Startup

Step 0 - What Chemicals Do I Need For A Freshwater Salt System Start up

Having everything ready before start up is essential. These are the things you need to start up a Freshwater Salt System.

  1. Freshwater Salt Cartridges
  2. Clean Screen Pre-Filter
  3. Freshwater 5-Way Test Strips
  4. Freshwater Stain & Scale Defense
  5. Freshwater pH/Alkalinity Up or Freshwater pH/Alkalinity Down
  6. Freshwater Spa Salt
  7. Freshwater Salt Test Strips
  8. Freshwater Chlorine Granules
  9. Mineral Spa Sanitizer Cartridges (Optional)
  10. Vanishing Act Pillow

All products for startup and maintenance of a spa using the Freshwater Salt System can be found here.

Step 1 - Freshwater Salt System Cartridge Installation

Remove The Salt Cartridge Cap

The first step to starting up the Freshwater salt system is to take the cap off the Salt Cartridge Slot. The Cap will be located on the top of the spa next to the filter cavity.

The cap can be removed by rotating the cap and lifting up.

Salt Cartridge Cap

Remove The Factory Plug

 If this is the first time you are starting up your spa you will need to remove the plug that comes with the spa. To do this press the button on the top of the plug and lift it out.

Salt Cartridge temp plug removal
Removal of factory installed plug

Insert The Salt Cartridge

Press the button on the top of the cartridge and insert into the slot. Make sure that either the plug or a cartridge is installed at all times.

Once the cartridge is inserted release the button on the top and give the cartridge a very light tug to make sure it is locked into place and seated properly. If it pulls out of the slot push the button on the top and re-seat the cartridge. Once the cartridge is seated, replace the cap.

Note: Cartridges should be replaced once every four (4) months.

Installing The Freshwater Salt Cartridge
Installing the Cartridge

Step 2 - Filling Your Spa

Hot Tub Fill Water Quality

Filling your spa with the best quality of water will help ensure your spa runs smoothly and will save you both time and money  on maintenance. The best way to do this is by ensuring the water entering your spa is filtered with a high quality pre-filter. The Freshwater Clean Screen Prefilter is highly recommended for this as it reduces metals before they enter your spa. It is also specifically designed for Hot Spring Spas

Where To Add The Water To Fill The Spa

When filling your spa it is essential that it is done through the filter cavity. Filling your spa from the seating area can cause a problem called “air lock”.

Air lock occurs when air is trapped in a pump preventing it from moving water as it should. When this occurs you will hear the hum of the pump but see nothing coming out of the jets. This can damage your spa’s pumps.

Filling the spa through the filter cavity flushes water through the pipes to help prevent air lock from occurring. To do this first remove the filter cover, then find the gray filter cap.

Twist off the gray filter cap and you will find a hollow tube. This is where you should fill the spa from.

Allow the water from the garden hose to flow through this tube in the filter housing. Do not shove the garden hose in as this can cause problems.

Remove the Gray Filter Cap
Grey Cap Remove From Filter
Hollow Tube Visible

How High To Fill The Hot Tub With Water

The spa should be filled until the water level is one (1) inch above the highest jets in the spa as shown below. As the spa is filling it is highly recommended to add an initial dose of Freshwater Stain and Scale Defense. This is recommended even if you have used the Clean Screen Pre-Filter to ensure your water’s metal levels are as low as possible.

How High to Fill A Hot tub with water

Testing The Spa's Pumps & Jets

Once the water is at the appropriate level turn off the hose and turn on the power to the hot tub. It will take a few minutes for the spa to run through its priming cycle and for the controls to become available.

Once the controls come up first test the pumps to make sure no air lock has occurred. This can be done through the jets menu. The Highlfe Series touch screen control and the Limelight Series spa  controls are shown below with the buttons for the jet menus circled.

Highlife Series Controls With Jet Menu circled
Limelight Controls with Jet Menu circled

Remember the goal of this step is to check for airlocks. You will know if an airlock has occurred if you turn on the jets/pumps and no water is moving in the spa. You will hear the pump but not see any water coming out of the jets.

If an air lock occurs turn off the pump immediately and use your garden hose to flush water through the gray stand pipe shown above. It may help to briefly turn on the pump while flushing water through the lines.

If you do have to flush more water through the filters do not have the hose pushed into the stand pipe as the pump can pull the hose into the spa plumbing and cause damage when the airlock is suddenly flushed out.

Step 3 - Initial Settings And Control Checks

Setting The Spa's Temperature

At this step the power should be turned back on to the spa.

The salt system needs a temperature of at least 95 degrees Fahrenheit to operate. Set your desired temp to your preference at or above that temperature.

Note that the higher the temp the less time you can safely stay in the spa. For example at 102 degrees Fahrenheit it is recommended to not stay in longer than 30 minutes with out getting out to cool off.

Setting the Temperature on a highlife Spa

Setting The Temperature on Highlife Spa Models

On the Highlife control panel tap the temperature (yellow circled in the illustration).

Then use the up or down arrow on the next screen to set the temperature.

Then press the home button in the top left corner.

Turn The Salt System Off - For Now

There are still a few more steps needed to be done before turning on the Freshwater Salt System.

So at this time it is important to ensure the system is turned off.

Setting The Temperature on Limelight Spa Models

On a Limelight Model Hot Spring spa control panel press the options button.

Then press the black button with a white dot next to the section of screen that says temperature.

Then using the inner buttons on the right side of the control panel adjust the temperature up or down. When done press the back button.

Turn The Salt System Off - Highlife Models

To turn off the Freshwater Salt System on a Highlife Model Spa, press the water drop shaped button on the control panel.

Then make sure the Salt System Output slider is set to zero. The colored wheel next to it will also say off.

If it is not off slide the output slider down until it says zero.

Turn The Salt System Off - Limelight Models

To turn off the Freshwater Salt System on a Limelight Model, start by pressing the options button.

Then the black button with a white dot in it next to the screen that says Freshwater Salt System.

Lastly check that the output level is zero.

Step 4 - Balancing The Spa's Water Chemistry

Testing The Water With A Test Strip

Now that water is in the spa you need to check certain measurements that are important to a hot tub. This is the part of hot tub maintenance where you can relate yourself to a doctor on a medical drama on TV. Where they are taking care of a patients vital signs like heart rate, blood pressure, and breathing rate, your job is to look after your spas pH, Alkalinity, Calcium Hardness, and chlorine levels. Like human vital signs these factors are very important for a hot tub to have a long and healthy life.

The first thing to do to take care of these measurements is to know where they are. To do this use a Freshwater 5-way Test Strip. At his point we are concerned with the pH, Alkalinity, and calcium hardness.

Testing Spa Water With a Freshwater 5-way Test Strip

How to Use A Test Strip

Reading a spa test strip is an important part of startup and regular spa care. If you are unfamiliar with how to use test strips check out our article on how to read a test strip.

Ideal Levels For Spa Water Using The Freshwater Salt System

The Freshwater Salt System requires slightly different water chemistry to function properly than a normal spa. The target or ‘OK’ ranges for each of the standard water chemistry levels is shown in this chart.

Most standard spas primarily worry about pH, Alkalinity and Sanitizer (chlorine, bromine, etc). The Freshwater system has two others that are of critical importance to the function and lifespan of the salt system. The salt level and the calcium hardness level.

Salt will be converted into chlorine and will be added at startup. The calcium hardness is extremely important because if it gets too high it will damage your salt cartridges.

Freshwater Salt System Ideal Water Chemistry Levels
Freshwater Salt System Ideal Levels

Adjusting The pH & Alkalinity

At this point the pH and Alkalinity should be adjusted first to meet the “ok range” in the table above. The other values will be adjusted later.

Use Freshwater pH/Alkalinity Up and Freshwater pH/Alkalinity Down to adjust the pH and Alkalinity.

If you are unfamiliar with how to adjust pH and alkalinity check out our article on how to balance your pH and Alkalinity.

How To Add Chemicals To A Hot Spring Spa

Play Video about How to Add Chemicals to a Spa

Adding Salt To The Water

Before adding salt to the water, first look up either online or in you owners manual how many gallons of water your spa holds.

You will need to know the number of gallons to compare to the chart on the back of the Freshwater Salt Bag. The chart will tell you how many cups of salt to add.

Freshwater Salt Bag Chart

Add The First Half Of The Salt

Turn on the jets in the spa and remove the filter lid. To ensure you don’t accidentally add too much salt begin by adding half the salt listed on the chart one cup at a time to the spa’s filter cavity.

Once half the salt is added wait 5 minutes for the salt to fully dissolve.

Adding Freshwater Spa Salt To A Hot Spring Spa

Using Salt Test Strips

After the 5 minutes have passed, turn off all of the pumps, then use a salt test strip to check the salt level.

Checking Salt Level With a Freshwater Salt Test Strip

Adding The Rest Of The Salt

If the test strip shows the salt level is below 1,750 ppm:

  1. Turn on the jets add one cup of salt.
  2. Wait 5 minutes
  3. turn off the jets
  4. Re-test with a salt test strip.


Repeat these steps until the salt level reaches 1,775 ppm. Do not add more salt than is recommended for your number of gallons.

If by accident the salt levels get too high, you will need to drain some of the water from the spa and add more filtered water back in to dilute the salt levels to where they are supposed to be.

Adding Freshwater Spa Salt To A Hot Spring Spa

Step 5 - Adding Initial Chlorine

Sanitizing your hot tub is an essential step as it keeps your water safe until the Freshwater Salt System is ready to handle the workload. To do this, turn on the jets and add the recommended amount of chlorine on the back of the bottle of Freshwater Concentrated Chlorine Granules. The goal is to have a reading of five (5) ppm chlorine on a Freshwater Five Way Test Strip.

Checking Chlorine Levels Using A Freshwater 5-way Test Strip

Mineral Spa Sanitizer Cartridges

At this step you can also add a Mineral Spa Sanitizer Cartridge to help maintain your sanitizer levels.

  1. It helps prevent bacteria from growing
  2. By minimizing the amount of bacteria forming in the spa, we can minimize the amount of chlorine/Salt Consumption required to keep water clean.
  3. Each Mineral Sanitizer Cartridge lasts 4 months.
  4. They drop into the tube under the grey filter cap used for filling the spa.
Freshwater Mineral Sanitizer cartridge with box

Step 6 - Soften The Water

As mentioned earlier keeping the calcium hardness levels low is essential for the Freshwater Salt System.

Calcium buildup also know as hard water can damage spa equipment. It can lower the effectiveness of the Salt System Cartridge and even shorten the life of the cartridge.

If your calcium hardness levels show higher than 75 ppm on a Freshwater Five Way Test Strip you need to use a Vanishing Act Pillow.

Vanishing Act Pillow come in two sizes, Regular and XL. If your spa has a large number of gallons or your local water is extremely hard you may want to use the XL size.

The ideal goal is to get the calcium level to 50 ppm on a five way test strip. However, calcium levels anywhere between 25-75 ppm is ok.

reshwater Vanishing Act

How To Use A Vanishing Act

Play Video about reshwater Vanishing Act

Step 7 - Turning On The Salt System

It’s now time to turn on the system. Follow the same steps as in the step 3 section “turn the salt system off” to get to the salt system menu.

Once there you will select an output setting either with the slider on Highlife spas or the right inner buttons on the limelight series. Selecting an output level above zero turns the system on.

Output settings will vary based on how many gallons of water your hot tub holds. 

Use the chart to see what the recommended initial output setting is for your spa.

Turning On The Salt System - Highlife Spa Models

On Highlife spa models tap the water drop shaped icon to enter the Freshwater Salt System Menu.

Once there tap above the zero (0) on the output level control to set the system to the appropriate level.

Tap below the number if you need to lower the output level or turn the system off in the future.

Once the output level is set the Salt System will now begin to generate chlorine on its own.

Turning on the Freshwater Salt System on a highlife spa

Turning On The Salt System - Limelight Spa Models

On a Limelight Spa Model:

  1. Press the option button
  2. Then press the black button with a white dot on it that is next to where it says Freshwater Salt System on the screen.
  3. Then press the black button with a white dot that is top right of the screen to change the output level.
  4. Using the black buttons with white dots on the right side of the screen you can raise or lower the Freshwater Salt System’s output level.


Once the output level is set the Salt System will now begin to generate chlorine on its own.

Step 8 - Recheck The Water After 24 Hours

Twenty four (24) hours after you have set the salt system output level you will need to check it again with a Freshwater Five Way Test Strip. The chlorine should be holding at 3ppm or above.

If the chlorine level has dropped below 3 ppm add more of the Freshwater Chlorinating Granules to raise the level to 5 ppm and press the boost button on the salt system. The Freshwater Salt System boost button will temporarily increase chlorine production and then drop back to normal.

You will need to repeat this step every twenty four hours until the spa is holding at least 3 ppm of chlorine on a test strip.

It may take a few days for the Freshwater Salt System to independently maintain the chlorine level, depending upon the quality of your fill water, how many people get in, and how much you use it on those first few days.

If the level of chlorine goes above the “OK” range you will need to turn down the salt system output level and wait for the water levels to drop back down to the “ok” range before getting into the spa.

Testing Spa Water With a Freshwater 5-way Test Strip