Hot Tub Mineral Sanitizers – The Complete Guide

Michael Keenan


Hot Tub Water Chemistry

Taking care of your hot tub water can be overwhelming with all the different types of sanitizing systems available. While chlorine sanitizers are still the popular choice, mineral sanitizers are gaining popularity because of their numerous health benefits coupled with the added advantage of low maintenance.

You might have a hard time choosing the right fit for you when it comes to deciding on a hot tub sanitizing system. Choosing the right sanitizer is key.

In this article you’ll learn about how hot tub mineral sanitizer works, it’s benefits and drawbacks. I’ll look at the different types of spa mineral sanitzing systems, how to switch over and shocking your hot tub.

Hot Tub Mineral Sanitizers main guide

Quick Answer:

Mineral sanitizers are gaining popularity as a hot tub sanitization system because of their numerous health benefits and low maintenance requirements. They use natural minerals like silver, copper, and limestone to disinfect the water while reducing the need for chemical sanitizers like chlorine or bromine.

There are various types of spa mineral systems available such as filter sticks, floating dispensers, and inline systems. However, there may be drawbacks such as oxidation stains or higher overall costs depending on usage. Keep reading for all the details.

How a Hot Tub Mineral Sanitizer Works

Mineral sanitizers are a low chlorine alternative to traditional hot tub sanitizing systems. They make use of natural minerals like silver and copper to sanitize the hot tub water.

The antibacterial properties of silver and the uses of copper as an algaecide are harnessed to create a sanitizing system that is easier on the environment as well as on your body.

Some mineral sanitizing systems also include limestone. Limestone absorbs acid from chlorine and also maintains pH levels, keeping the hot tub water stabilized.

Benefits of Hot Tub Mineral Sanitizers

Improves Water Quality

Using chlorine as the main sanitizer drastically impacts water quality. Chlorine makes the water harsher on your skin, hair and swimwear. The water feels silkier when using a mineral sanitizer as they use very little chlorine.

water quality

Less Chloramines

When the chlorine in the water has been used up, it interacts with the bodily fluids and other debris in the water to form chloramines. Chloramines cause skin irritations, aggravate pre existing skin conditions like eczema, cause drying and reddening of eyes and a host of other health problems.

Since the amount of chlorine being used in mineral sanitization is only half the usual quantity, it reduces the creation of chloramines. Chloramines are also responsible for the yucky ‘pool smell’, which means mineral sanitizers make your hot tub stench-free.

Low Maintenance

Unlike traditional chlorine and bromine systems, you don’t need to constantly test chemical levels and measure out the proper quantity of sanitizer every time you need a top up.

Mineral sanitizers come in the form of easy to use cartridges that only need to be replaced as and when they are empty. This makes maintaining a clean and clear hot tub a lot easier.

less maintenance work

Drawbacks of Hot Tub Mineral Sanitizers

While there are many benefits to mineral sanitizers, there are a few rough patches that you may hit if you do decide to switch to a mineral sanitizing system.

Oxidation Stains

When copper oxidizes it leaves a greenish stain on objects. Copper is one of the major minerals in your mineral sanitizer cartridge. Sometimes your water source might also contain a fair amount of copper.

If the copper content in your hot tub is very high, oxidation can result in your hot tub shell being covered in green stains.

Dependant on Chlorine or Bromine

Mineral sanitizers alone cannot completely keep bacteria and algae at bay. They need a little boost from chemical sanitizers like chlorine or bromine to function effectively.

While the use of chlorine or bromine is halved in a mineral sanitizing system, you still have to depend on them if you want your hot tub to remain germ free.

Might Be Expensive

Mineral sanitizers are less expensive and last longer than chlorine or bromine. However, in the case of mineral sanitizing systems, you will have to spend money on both mineral sanitizers as well as chlorine or bromine.

If your hot tub is used frequently by a lot of people, you might ultimately end up spending more money to keep it clean.

Types of Spa Mineral Sanitizers

Mineral sanitizers don’t need to be measured like chlorine or bromine; they come in the form or cartridges or sticks that only need to be replaced when they run out.

These are the different options you can choose from when switching to a mineral sanitizing system:

Filter Sticks

This is the easiest option if you are considering a mineral sanitizing system for your hot tub. They come in the form of sticks that contain minerals. You only need to insert the stick into the hot tub filter and you’re done.

When water flows through the filter it will also flow through the filter stick releasing the minerals into your hot tub. You only need to replace the sticks once they are empty.

Floating Dispensers

Floating dispensers are another easy and low cost option. These come in the form of floating dispensers to which you can connect a mineral cartridge and a chlorine or bromine cartridge.

They float around the hot tub releasing minerals consistently. They last at least 6 months. The dispenser turns on its side when cartridges are empty, letting you know exactly when to replace them.

floating mineral dispenser

Inline System

This type requires you to have an inline system pre installed in the plumbing of your hot tub. This option requires some investment either at the time of installing the hot tub or when you decide to switch to a mineral sanitizer.

The inline system is a compartment in your plumbing into which you can slide the mineral sanitizer cartridges. Not all hot tubs come with an inline system, so this option might be more tricky to implement than the others.

How to Switch to Mineral Sanitizers

We have seen that maintaining a mineral sanitizing system is relatively effortless and easy. However, you need to get your hot tub ready before adding minerals to it.

These are the steps you need to follow if you are planning to switch to a mineral sanitizing system:

1. Lower the Chlorine and Bromine Levels

If you are switching from a chlorine or bromine-based sanitizing system to a mineral sanitizer, you need to let the levels of chlorine and bromine in your hot tub water drop considerably.

High levels of chlorine or bromine can reduce the effectiveness of mineral sanitizers. The chlorine should only be 0.5 parts per million (ppm) and the bromine should only be 1 ppm.

2. Test Water Hardness

You need to test your water source to make sure that the hardness of water is below 250 ppm. In case your water is very hard, you can use a hose filter to filter out the hardness causing elements.

3. Test the Metal Content of the Water

If there is a high concentration of metals like copper or iron in your hot tub water, it can cause discoloration of water and staining of the hot tub basin. Take a water sample from your hot tub to your local pool center and make sure that the metal levels are not too high.

If you have high metal content you can add a metal sequestrant to the water to remove the metals. Sequestrants are chemicals that bind liquified metal salts which helps in filtering them out of the hot tub.

4. Balance the Water

The chemical composition of your hot tub water is very important to keep the water clean, enhance the life of hot tub equipment and make sure that the sanitizers work efficiently.

The ideal chemistry of hot tub water is as follows:

  • pH level: 7.5 is the ideal level, but anywhere between 7.4 and 7.6 is acceptable
  • Calcium hardness: 175 ppm – 250 ppm
  • Total Alkalinity: 80 ppm – 120 ppm

5. Add the Mineral Sanitizers

Once you have tested your water and stabilized it you can add your mineral sanitizer to the hot tub water. You can choose filter sticks, floating dispensers or inline systems to sanitize your hot tub.

You will need to replace the sanitizer cartridges at least once in four months. They also need to be replaced whenever you drain, clean and refill your spa.

6. Add Partner Sanitizers

Mineral sanitizers are good at keeping your hot tub water clean. But to fully keep the bacteria and algae at bay you need to use mineral sanitizers along with either chlorine or bromine. It is difficult to manage a hot tub without any chemicals at all, but you can reduce chemical use.

These chemical sanitizers supplement the functioning of mineral sanitizers and help keep your pool germ free. However, make sure that you don’t increase the levels of these chemical sanitizers as higher levels can reduce the effectiveness of the mineral sanitizers.

Shocking a Mineral Hot Tub

Shocking hot tub water is essential to kill off any bacterial or fungal growth and free up the chlorine elements that were used during sanitization.

You need to shock your hot tub regularly. If your hot tub is getting a lot of use, you might need to shock it more frequently.

Before you add the mineral sanitizer, you need to use a chlorine shock to kill any bacteria or algae that might be lingering in the hot tub. Learn how long to wait after using shock in your tub. Once you have switched to mineral sanitizers you can use non-chlorine shocks for your hot tub.

You will need to use a chlorine shock occasionally to keep the hot tub squeaky clean. You don’t want to over shock your hot tub – read this guide. Just remember to test your water and stabilize it whenever you use a chlorine shock.

shocked cat


How often do I need to change my hot tub’s mineral sanitizer?

Mineral sanitizers should be changed every three months or when the mineral levels become low, whichever comes first.

What type of sanitizer is best for my hot tub?

Natural mineral-based sanitizers are generally considered best for hot tubs as they have fewer risks associated with their use than other chemical options.

Are there any risks associated with using mineral sanitizers in a hot tub?

If not used properly, there is a risk that mineral sanitizers can cause scaling and staining on your hot tub’s surfaces. It’s important to follow manufacturer instructions carefully when using them.

How can I tell when it is time to replace the mineral sanitizer in my hot tub?

If you notice that your hot tub’s water is becoming cloudy or discoloured then this may be an indication that it is time to replace the mineral sanitizer in your hot tub. You should test the mineral levels regularly and make sure that they stay within an acceptable range for optimal performance of the product.

In Conclusion

Mineral sanitizing systems are becoming increasingly popular due to their health benefits, low maintenance and improved water quality. They are great for hot tubs and pools.

They come in the form of easy-to-use cartridges or sticks that need to be replaced when empty, but they require a boost from chemical sanitizers like chlorine or bromine for maximum effectiveness.

Switching to a mineral sanitizing system is easy enough as long as you follow the tips above. And remember to always test the water after any changes. Don’t get rid of the shock just yet! It’s still good practice to shock your tub every so often just to keep things clean and healthy.

Hot tubs should be a place to relax and unwind after a long day. But if an hour in your hot tub strips you dry of natural oils and leaves you with red eyes, it might not be so relaxing.

Switch to a mineral sanitizer system that lets you reap the benefits of your hot tub without having to worry about your skin, hair and eyes.

michael keenan author

Author - Michael Keenan

I'm Michael Keenan the owner and creator of the Outdoor Care Guide. I'm a trained horticulturist with over 30 years of experience in pool care, plant care, and landscape care! Seemed like a good idea to share - I think I can make your life easier and save you some time and money!