The best way to enjoy your hot tub is with water that’s clean, clear, and ready when you are. One of the most important factors in keeping your spa water safe and inviting is choosing the right sanitizer.
Two of the most common hot tub sanitizers are chlorine and bromine. Both can kill bacteria, prevent algae growth, and keep your water balanced. But which one is best for your hot tub — and for you?
Whether you’re looking for your first spa or considering switching sanitizers, understanding how these products work (and what they work best with) can help you make the right choice.
Why your sanitizer choice matters
Sanitizer is essential for keeping hot tub water safe. The warm water is the perfect environment for bacteria to grow — unless you treat it properly. Chlorine and bromine both work to destroy contaminants, but they do so in different ways. They also react differently with your hot tub’s filtration system and your body.
Master Spas hot tubs feature advanced filtration, including the mineral-based EcoPur Charge system. Designed to reduce the need for harsh chemicals, this system works most effectively when paired with chlorine granules.
Master Spas also has offers a saltwater system — giving you even more flexibility in how you care for your water. The Master Clear Salt System is a smart system that automatically monitors and balances sanitizer levels.
What to know about using chlorine in a hot tub
Most people are familiar with chlorine because it’s used in swimming pools and cleaning products. But the chlorine you add to your hot tub is specifically formulated for spa use.
How it works: Chlorine acts as an oxidizer, breaking down and destroying unwanted substances like sweat, body oils, and bacteria. As it works, it can produce chloramines, which are responsible for that “chlorine smell.”
However, the EcoPur system helps remove chloramines from your water, keeping it fresh and clean-smelling.
When to add it: Many hot tub owners add a small dose of chlorine after each use, while others prefer to add it once a week. How often you need to add sanitizer depends on how frequently you use your hot tub and how many people are using it. Aim for chlorine levels between 1.5 and 3.0 ppm.
Best type of chlorine: Master Spas recommends using dichlor chlorine granules, which dissolve quickly and are safe for spa components. While tablets or floaters may seem more convenient, they can lead to over-chlorination and damage your spa if left in the water too long.
Caution: Using the wrong type of chlorine can affect your water chemistry and damage your spa’s components.
Is bromine OK for a hot tub?
Bromine is another popular sanitizer option and is often chosen by people with sensitive skin. Like chlorine, bromine kills bacteria and keeps water clean. But it works a bit differently.
How it works: Instead of oxidizing contaminants like chlorine, bromine ionizes them. This process produces bromamines, which are less irritating than chloramines but can still build up in the water.
Bromine also dissolves more slowly than chlorine, which means it can linger on skin or swimwear. If you use bromine, it’s a good idea to rinse off after soaking.
Water care routine: Bromine needs to build up to a consistent level, creating a “bromine reserve” for effective sanitation. Most people add bromine every few days, depending on usage. Keep bromine levels between 3 and 5 ppm.
Why Master Spas recommends chlorine: While bromine can work in a hot tub, it’s not the best fit for mineral-based filtration systems like EcoPur. For the most effective, low-maintenance water care, chlorine is the preferred choice for Master Spas hot tub owners.
Chlorine vs. bromine: How to choose
If you’re deciding between chlorine and bromine, here are a few things to consider:
| Feature | Chlorine | Bromine |
| Dissolves quickly | ✓ | X |
| Less likely to stick to skin/swimwear | ✓ | X |
| More sensitive to pH changes | X | ✓ |
| Can be added after each use | ✓ | ✓ |
| Leaves less smell | ✓ | X |
| Works best with EcoPur Mineral System | ✓ | X |
Keeping hot tub water care simple
Hot tub maintenance doesn’t have to be complicated. With the right system and water care products, you can spend less time managing your spa and more time enjoying it.
Want to learn more about how the EcoPur Charge filtration or the Master Clear Salt System works? Or are you curious how much a hot tub might cost? Request a quote from your Master Spas retailer today.