Should I Put Antifreeze in My Hot Tub?


If you got a hot tub less than a year ago, you might still be in new territory exploring different aspects of being a hot tub owner throughout the year. Closer to winter, you might consider closing the hot tub. If the cold lasts longer than two months, you can save money by winterizing your hot tub, for which antifreeze is necessary.

You should put antifreeze in your hot tub if it is a non-toxic kind. Toxic antifreeze can cause complications as its residue can harm people once the hot tub is back in use. To be safe, look for antifreeze formulated specifically for swimming pools and hot tubs, as it is designed to be safer.

In this article, you will learn more about both types of antifreeze, and you can differentiate them. Among other things, you will also learn the steps you must take before pouring antifreeze into your hot tub. Finally, you’ll discover the simplest way to find out if you should winterize your hot tub or keep it running. But before that, let’s look at the pros and cons of putting antifreeze in a hot tub.

Pros of Putting Antifreeze in a Hot Tub

Antifreeze is a staple of winterizing hot tubs, aboveground and inground pools. Its advantages are the same as the advantages of shutting down a pool or a hot tub during winter. Since pool closing is a country-wide phenomenon, antifreeze is widely used for the following advantages.

You Can Safely Shut Down the Hot Tub

A hot tub needs to run 24/7 until you properly shut it down. Antifreeze ensures that your tub’s plumbing isn’t compromised by the cold. Shutting down your hot tub entails draining out a lot of the water and replacing the liquid stopped in the tub’s plumbing with antifreeze. If you turn off the heat pump of your hot tub during winters, your tub’s pipes are at risk of hemorrhaging due to water expanding as it freezes. A liquid with a much lower freezing point is better suited to occupy the pipes.

It Saves Electricity

If electricity is expensive and your winters are long, using antifreeze to protect your hot tub’s pipes from freezing is a much better option than using your heat pump to combat the cold. According to our calculations, you can save money closing your hot tub if winters in your area are longer than two months. The definition of winter can be relative, but what we consider winter is when your tub’s pipes can freeze when the heat pump is turned off.

It Extends Your Heat Pump’s Lifespan.

Finally, the greatest fiscal advantage of antifreeze is that it takes on the responsibility of the heat pump when it comes to preventing water from freezing in the hot tub’s pipes. A heat pump incurs wear and tear during the course of its operations. But if you use antifreeze to protect the hot tub’s pipes, you can safely turn off the heat and extend the pump’s lifespan in the process.

Cons of Putting Antifreeze in a Hot Tub

Nothing is without its drawbacks, and antifreeze in hot tubs is no exception. While it is standard procedure to pour this substance into one’s hot tub when closing it, you have to consider the two main drawbacks that might persuade you to opt for the alternative: keep the hot tub running on high heat throughout the winter.

Inconvenient to Flush Out

When you pour antifreeze into your hot tub’s plumbing, you safeguard the pipes from warping, but you also effectively shut your hot tub. After this, you cannot spontaneously decide to return to hot tub use; you need to go through the entire process of flushing out the antifreeze and reopening your hot tub. Often, antifreeze is a nail in the season-long coffin of hot tubs, and one gives up usage privileges for the winter.

Risk of Toxic Exposure

Not all antifreeze is made alike, and some varieties are toxic. If you do not choose your antifreeze carefully, you might be at risk of toxic exposure. Check out the section below for more on the two categories of antifreeze and how you can shop safer to offset this drawback.

Types of Antifreeze

Non-toxic antifreeze

This antifreeze can be poisonous but is safe for skin contact at least in moderate quantity. It is often used to prevent freezing in systems that come in direct contact with the human body. The chief among these is swimming pools. From swimming pools to garden plumbing, anything that introduces water to organic bodies is best preserved with non-toxic antifreeze.

Toxic antifreeze

This antifreeze is cheaper to make and is widely available to protect systems that do not introduce liquids directly to the human skin. Unlike shower pipes and swimming pool plumbing, the contents of a car radiator won’t necessarily touch the human body. Antifreeze for such systems does not need to be non-toxic. Antifreeze used in cars, quad-bikes, and RVs is often this variety though non-toxic antifreeze can also work in these systems.

Which Antifreeze Do You Put Into a Hot Tub?

By now, it must be evident that you must pour non-toxic antifreeze into your hot tub. The only exception is if you don’t use the hot tub in a standard manner. If the tub is, for example, used to wash large items, then the antifreeze might not have to be non-toxic. There have been reports of old hot tubs being used as large laundromats for sofas and carpets. 

Even in those instances, toxic antifreeze would be risky as traces of the substance might get deposited onto the products that touch exposed human skin. All in all, it is almost always safer to opt for non-toxic antifreeze.

Final Thoughts

Pouring antifreeze into your hot tub is a stand-in for shutting your hot tub during the winters. If you are a new hot tub owner with no neighbors who have a hot tub, looking for guidance regarding hot tub operation during winters in your area can be a little confusing. In some states, hot tubs should definitely be shut down. In others, they can be run without significant electricity expenses. To know what’s best for your area, simply list hot tub spare parts on Craigslist. Others with hot tubs will call you, which is when you can ask them whether they shut down their hot tubs during winters or use them.

Jed Arnold

Jed spent every year from the ages of 15 - 22 as a Lifeguard (Red Cross) and ages of 17 - 22 as a Certified Pool Operator (CPO). Between working for over a dozen facilities and owning a pool, he carries over a decade of pool experience.

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