Why Does My Hot Tub Water Smell Like Rotten Eggs?

Many of us hot tub owners have come home from a hard day’s work, lifted the hot tub lid, and thought, phew, why does my hot tub water smell like rotten eggs?

The smell of rotten eggs in a hot tub is most likely hydrogen sulfide gas, which is usually caused by decaying organic matter or bacteria called biofilm. This can be present in the water but more likely is in the plumbing and equipment, and not visible. Luckily, there’s an easy solution.

That smell of sulfur is quite noxious and is a sure sign that something is not right.

But before you do anything, you should make sure that the smell is coming from your hot tub and not from your drains. Sewer gas has a similar odor, so make sure that is not the cause of the smell.

To learn what to do next, read on.

Why Does My Hot Tub Water Smell Like Rotten Eggs lg

Ready to Spend Less Time On Maintenance and More Time Enjoying Your Hot Tub?

Let’s face it. Balancing the water, cleaning filters, dealing with rashes, and trying to figure out which chemicals to buy and add can make you feel more like a chemist than someone who just wants to relax after a long hard day!

That’s exactly why The Hot Tub Handbook and Video Course is so valuable!

This is from Matt over at Swim University and he developed it for people looking to save money, time, and frustration. His tips on chemicals can save you $100/year just by making sure you buy only what you need.

So if you’re ready to stop being confused or frustrated with your hot tub and start spending more time in it, check out The Hot Tub Handbook and Video Course.

Just click that link to learn more on their website.

Is there sulfur in my hot tub water?

Sulfur is not typically present in hot tub water. The smell is most likely hydrogen sulfide (H2S) gas, which is harmless and will dissipate with the lid off for a few minutes as the gas quickly disperses into the atmosphere. However, it could be a symptom of another problem.

However, just because the smell is harmless doesn’t mean something isn’t wrong.

The smell is often caused by the decay of organic matter, but it could also be corrosion of metallic parts. So to find out what your problem is, you need to ‘troubleshoot’.

In most modern hot tubs, there are only a few, if any, metallic parts to corrode, but don’t rule it out straight away. Look at the more likely event first.

When we jump into a hot tub, especially with kids, we bring in all sorts of organic matter with us. This can be plant or animal-based, but all organic matter derives from living things, unlike the deodorants and body lotions we apply ourselves.

So even if you shower beforehand, you can still bring leaves and bugs in with you. Even dead skin can add to the build-up.

Bugs and plant life can also get into your hot tub if you leave the lid off for a while before getting in, or even when you’re in there, so it is hard, if not impossible, to keep them out.

So, check your filters and chemical balance first, then look to see if you have any rusting elements if this is okay.

How do I stop my hot tub water from smelling like rotten eggs?

To eliminate a rotten egg sulfur smell in the hot tub water, change the water every 3 months and perform a biofilm cleanout every time. In addition to maintaining proper water chemistry, rinse filters every 3 weeks and do a filter deep clean every 3 months and replace them annually.

It is important to introduce and maintain a rigorous regime to keep your water clean, clear, and smelling sweet. 

The filter on your hot tub is the first line of defense in terms of keeping all the nasty things from getting into the plumbing.

You should clean the filter every 3 weeks if you use it a lot, once a fortnight for lighter use. This can be just a matter of hosing it down, but you need to get right into those pleats.

Check out this Filter Flosser on Amazon – it’s made for this situation, and you just connect it to your garden hose.

Then you should check the sanitizer levels and pH and alkalinity levels too. If you’re getting a smell of rotten eggs, it is more than likely caused by an imbalance, so you will need to hyper-chlorinate.

Hyper-chlorinating the water will give your water an extra dose of sanitizer.

This is known as shocking the water, and you need to bring the chlorine level up to 100 ppm or more to kill off the sulfur bacteria. It is important to get rid of all bacteria; otherwise, the problem will return, so keep up with the maintenance program.

I do a biofilm clean-out every time I change my water.

To do this, I simply add about 8oz. of Oh Yuk! Healthy Hot Tub Cleaner from Amazon to the water. Then I leave the lid off, take the filters out, and run the jets for 1 hour. I restart the jets as needed since they time out occasionally.

Then I rinse or wipe off any residue along the waterline, drain, and wipe down the hot tub before refilling and balancing the water.

Is it bad to get in sulfur water in a hot tub?

A sulfur smell in hot tub water is not toxic and does not pose a health hazard in itself. However, the gas that can develop from sulfur bacteria, H2S, can irritate your mucous membranes and respiratory tract. More acute symptoms include headaches, nausea, and convulsions.

In the concentrations likely to be experienced in your hot tub, it is not so much the sulfur or the hydrogen sulfide gas that will cause you harm; it is the bacteria in the water.

Getting into any smelly water is not a good idea.

In a recent article, I discussed what makes hot tub water cloudy and smelly, and you can see this by clicking on the link. Hot tubs provide the ideal environment for bacteria to develop, and this can lead to diseases such as folliculitis and, worst-case scenario, Legionnaires’ Disease.

Just click that link to get all the details on my site.

So, you need to get the water cleaned up before going anywhere near it, and that involves shocking it. You can use chlorine or a non-chlorine shock for this.

It is best to leave the hot tub with the jets running and the lid off for 30 minutes or more after adding any chemicals. That will help to get rid of other gasses that are likely to develop.

Will chlorine get rid of a sulfur smell in my hot tub?

Chlorine shock or sanitizer, as well as bromine sanitizer, will kill bacteria in hot tub water that can lead to a sulfur smell. However, if biofilm is present in the plumbing, that can quickly render chlorine and bromine inert, so it’s best to perform a biofilm cleanout then drain and refill the hot tub.

If that seems likely, just see my instructions 2 sections above.

If you are keeping up with your water maintenance, you may just get away with your regular shock treatment. But if you’ve let things slip a bit, maybe you’ve been away for a while, then you need to get down to some serious sanitization.

Cleaning the filter, checking the pH and total alkalinity levels, and making sure the water is in balance are all things you should do to get the water clean again.

Get rid of the bacteria, and you will get rid of the smell.

Run your jets for a while to purge the pipes and clean the pump as well. Bacteria can often lodge in your plumbing after a major problem.

If the situation reoccurs, it’s probably a good idea to change the water in your hot tub.

You should do this anyway every 3 or 4 months, so if it is getting close to that time, this is your best option. You should check out this recent article about changing the water. A hose will take about 2 hours to drain a large hot tub. But I drain mine in less than 15 minutes!

Just click the link to read it on my site and see how!

How can I make my hot tub water smell better?

Spa Crystals can improve the smell of hot tub water with none of the risks posed from Epsom salt or oil-based aromatherapy products. However, never use scented products to cover up a bad smell in a hot tub.

If you have had a problem with foul odors in your hot tub, you need to, first of all, make sure your water is clean and clear.

Don’t add products to disguise a smell.

Many people like to use their hot tub for aromatherapy, and the best way to do this is to add some essential oils such as lavender, tea tree, cinnamon, or cedar. However, you can’t just use any oils – it has to be a product made specifically for spas and hot tubs.

The Spazazz Spa Crystals on Amazon are perfect for enhancing a hot tub’s spa-like experience – just click on the link to see the full description and the latest prices.

The original Lavender Palmarosa fragrance, Grapefruit Orange, Green Tea Peony, Pomegranate, Coconut Vanilla, and White Musk Jasmine Vanilla are excellent choices for a fragrant and relaxing soak in the hot tub.

These lightly scented crystals help you relax, and the oil-free formula does not leave any residues or affect the chemical balance of the water, nor does it clog the filter.

The only downside is if you have an outdoor hot tub, the aroma dissipates quickly, but at least it sets the mood and provides a lasting sensation.

Final Thoughts

I hope this gives you the information you need to deal with the smell of sulfur in your hot tub.

Don’t forget: you need to create a maintenance regime and stick to it to avoid bad smells and murky water.

If you need any more advice, just reach out to me – I’d be glad to help. And don’t forget to click on those links to read other associated articles here on my site.

Ready to Spend Less Time On Maintenance and More Time Enjoying Your Hot Tub?

Let’s face it. Balancing the water, cleaning filters, dealing with rashes, and trying to figure out which chemicals to buy and add can make you feel more like a chemist than someone who just wants to relax after a long hard day!

That’s exactly why The Hot Tub Handbook and Video Course is so valuable!

This is from Matt over at Swim University and he developed it for people looking to save money, time, and frustration. His tips on chemicals can save you $100/year just by making sure you buy only what you need.

So if you’re ready to stop being confused or frustrated with your hot tub and start spending more time in it, check out The Hot Tub Handbook and Video Course.

Just click that link to learn more on their website.


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Jeff Campbell