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How Often Should You Change Your Hot Tub Water?

There was a time when my hot tub water got really murky, smelly, and obviously needed to be changed. But when there aren’t obvious signs, how often should you change your hot tub water?

Change the water in your hot tub every 3-5 months depending upon the frequency of use. But also ensure proper water chemistry with regular testing & adjusting in addition to filter cleaning and replacing as needed. Poor water chemistry or a dirty filter will mean more frequent water replacement.

But there’s a lot more to know about how often to change your water. So we’ll also get into HOW to change it, what’s different about changing it in winter, and how to keep your water crystal clear all year long.

So let’s dive in!

Does hot tub water need to be changed?

Yes! Absolutely.

We fill our hot tubs with the garden hose typically, and that is often city water which is somewhat purified and chlorinated. However, when multiple people use it regularly, we contaminate the water with body oils, hair, flakes of skin, and even tiny particles of fecal matter.

Over time and use, the water gets dirty. 

Regular chemical maintenance keeps the water clean, pure, and clear. But after a while, there’s not much else you can do other than change your water.

Now you might wonder why it’s OK to swim in a lake that isn’t treated and doesn’t have the water changed.

But remember, that lake water is exposed to lots of oxygen and the sun’s UV rays. Those things combined with the flow of the water have a purifying effect on the lake water. There may also be movement in the water which freshens the water.

Your hot tub, however, mostly sits under a giant cover. The water sits perfectly still until you get in and turn the jets on.

Think about a lake or pond you’ve seen where there was no movement or under a shade tree. That water is usually algae-ridden and stagnant.

So with no chemicals whatsoever, you’d be putting yourself and your family and friends at great risk of infection.

Not sure how to treat your water or what to do if you have sensitive skin?

I have a recent article which goes into great detail on both those topics, including whether bromine or chlorine kills more of the bacteria and viruses that can live in hot tub water.

How often do you have to change the water in a hot tub?

I can tell you I change my water about every 5 months.

We have a family of 5 (including baby Layla). But in the heat of the Texas summer, we just don’t use it that often. So really, we use it regularly from October-May. And my wife and I probably like it and use it more than our 2 older daughters.

But if you want to be extra safe, changing it every 3 months would certainly get you all the protection you need from bacteria and other contaminants.

You can also simply go off of the appearance and smell of your hot tub water too. Or they have test strips available, just like the ones you use to test your water for pH and chlorine levels. This type of test strip tests for Total Dissolved Solids.

Luckily, those type of test strips are pretty cheap on Amazon (click to see them on Amazon). Just be aware that unlike some other brands, these work in about 30 seconds, telling you if it’s time to change the water.

When you do drain the hot tub, go ahead and plan to clean the empty shell with a bleach and water solution before you refill. Just mix bleach and water 1 to 1 and using a mop or long-handled scrub brush, just give the shell a once over.

Then rinse the tub out thoroughly before refilling.

There are, however, a lot of do’s and don’t about using bleach in a hot tub, including the one thing almost guaranteed to make it impossible to balance your pH and alkalinity.

So take a moment and click the link to read that on my site.

How often should you clean a hot tub?

Aside from changing the water regularly, it’s important to keep the chemicals balanced in your hot tub too.

This will ensure crystal clear water every time you use it. That also minimizes the risk for viral or bacterial infections or hot tub rash.

I like to check and adjust pH, total alkalinity, and bromine/chlorine levels every time I use the hot tub. Then I shock it a few times a month as well.

It’s also not a bad idea to wipe down the headrests and shell above the waterline every week with a white vinegar and water solution. That helps keep scum at bay which can build up just above the waterline.

Most hot tubs have a set schedule when the pump kicks on to continuously circulate the water during the day and night. This is a good thing and adds very little to your electric bill. It keeps the water moving, and going through the filter.

Of course, aside from that, every time you drain your hot tub, you should clean it before refilling.

Lastly, make sure to change your hot tub filter once every 1-2 years depending on how often you use your hot tub. I wrote a recent article which goes into great detail about that.

Not only do I cover how to know when it’s time to change the filter. But I also cover how to clean the filter periodically to extend the life of it. Just click the link to read it on my site.

How do I change the water in my hot tub?

This one often challenges people.

With the last hot tub we had before the one we have now, I had to get out the cordless drill and remove the wood siding. Then I had to close one of the valves and take one of the pipes off and direct it away from the tub before opening the valve to let the water out.

It was a pain!

The tub we have now has plastic siding, and I just take off 2 hand-screws on the corner panel and remove the panel to reveal a hose spigot.

Then I just attach a garden hose to the spigot and direct the hose away from the hot tub. Also remember that treated hot tub water can damage plants and grass, so drain it to an area you don’t care about.

Your hot tub might be different from either of those. But most likely if it’s a newer hot tub, it’s like what I just described with the plastic siding and hose. When in doubt, YouTube to the rescue!

That being said, if you want to skip all that and do it the easy way, get what I just got!

I’m so excited as I got a submersible drain pump with a 25′ hose. No siding to remove, no hoses to hook up.

Just plunk this thing in your hot tub and watch it drain in record time!

Normally my hot tub might take an hour or more to drain. But with this thing, I can drain in within 15 minutes! Great reviews, an Amazon’s Choice product, and free Prime shipping.

Do be aware, it has to be submerged before it will turn on. And, course, when the water gets down to the bottom, it will turn off, potentially leaving a small amount of water in your tub.

But that can easily be handled with a  wet-dry vac.

CLICK HERE to check current prices on Amazon on the submersible drain pump.

How do you change the water in a hot tub in the winter?

If you’re here in Texas like me, changing the water in winter really isn’t much different than any other time of year. After all, our seasons are hot and less hot.

But if you live somewhere that gets actually seasons, you might have very different conditions.

You may find you want to winterize your hot tub and believe it or not, antifreeze can help protect your pipes when you do that. Just follow all the steps in my recent article if you plan to do that.

But if you don’t want to just drain it and turn it off for the season, here’s what I recommend for cold-weather climates and changing hot tub water:

  • Do a normal water change about 4 weeks before when the 1st freeze would normally happen
  • Make sure your cover is free of tears and holes and does not get water-logged
  • Invest in a floating thermal blanket – A floating thermal blanket is simply a plastic blanket that literally floats on the water, keeping heat in and reducing strain on your heater and helping with your electric bill. Solar Cell makes one of the best-rated ones on Amazon. Just click the link to see their 8×8 cover which should be perfect for many hot tubs
  • Check the water level frequently – water leaks and freezing weather is not good for your hot tub. So check the water once or twice weekly if you aren’t using it regularly

If your cover does have minor tears or holes, why not fix it before they get worse and you have to pay a lot to replace it?

I recently wrote a step-by-step tutorial on how to fix holes and tears in hot tub covers. So take a moment and click the link to read that now on my site.

Final Thoughts

In this article, we took a look at the world of hot tub water.

Specifically, we looked at how often to change it and what you might need to do differently in winter. But we also looked at HOW to change the water as well as how to keep it crystal clear all year.

How often do you change your hot tub water?

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Jeff Campbell