Hot Tub Chemicals: Your Most Common Questions Answered

Water is the essence of your spa, so it should be fresh, clean and ready to go. 

Proper care and maintenance is critical to keep the water clean, clear and comfortable for you and your family, as well as to keep your hot tub running well for as long as possible. 

Below are the answers to some of the most common questions about spa chemicals and maintenance. 

Rest assured: Once you get the hang of it, cleaning your spa water is actually a simple process.

And in the meantime, Watson’s has been in the business for more than 50 years, so our friendly experts are here to help answer any question you have. 

We've also put together a free spa care & maintenance guide here. 

Do I really need to use chemicals in my hot tub? 

Yes. Proper maintenance is key to keeping your water clean, clear, comfortable and safe and to maximizing the lifespan of your spa, too. 

Unlike a bathtub, the water in your spa will stay there for up to three months. The water you fill it with might go through older city pipes that have copper or iron that needs to be filtered out.

Body oils, lotions, leaves and other debris or products can easily get into the water, too. 

Without proper care and chemicals to clean and balance your water, it can lead to unwanted side effects for both you and the spa -- from unpleasant buildup on the surface of your hot tub to restricted water flow to stinging eyes and dry skin. 

What chemicals do I need for my hot tub? 

The exact chemicals you need will vary depending on your exact spa, the water it’s filled with and the use of your hot tub. That’s why spa owners always start with test strips to evaluate the water. 

We have a complete guide to spa care and maintenance here.

Here is a brief overview, though, of some key spa chemicals that hot tub owners should keep on hand: 

• Sanitizer (like chlorine or bromine): A hot tub sanitizer kills bacteria and keeps your water pure. Granular chlorine or bromine are generally the best sanitizers. 
  
  
• A pH increaser and decreaser:  A low pH level makes your hot tub water acidic, so it can cause corrosion to the spa and discomfort to humans.  If it’s too high, though, it can eventually lead to scale on your filters, pipes and other equipment. 
• Sequestering agent: This helps remove and treat calcium, magnesium and other heavy metals from the water that can turn your hot tub water brown or green.
  

How soon can you use your hot tub after adding chemicals?

The general rule of thumb: Allow up to 30 minutes for the chemicals to begin circulating in the water and be fully absorbed. Keep the cover off, too, so any vapors can escape quickly. 

If your spa has a hot tub clean cycle, wait at least 10 minutes after the cycle finishes to allow for chemicals to dissipate before using your spa or putting the lid on.

If you jump in too soon, it can cause skin irritation, itchy eyes or other problems. 

What is the best thing to clean a hot tub with? 

Use a mild non-abrasive, non-sudsing cleaner and a soft rag to remove dirt build-up on the spa shell.

Baking soda is also great to clean tough stains on small surface areas.

Create a mild baking soda solution by mixing just 1 tablespoon of common baking soda with water, stirring until it becomes paste-like. Spread it on the stain and leave for approximately 20 minutes. Wash it off with water. 

More resources: 

A Beginner’s Guide to Spa & Hot Tub Care & Maintenance

Contact our spa experts with any questions 

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