Chlorine Smell In Your Pool Or Spa? Here’s What It Really Means

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Highlights:

A strong chlorine smell doesn’t usually mean too much chlorine, it often means not enough.
That “chemical smell” is typically caused by chloramines (used-up chlorine), not fresh sanitiser.
Low free chlorine allows contaminants to build up - increasing smell and irritation.
The solution? Test your water, shock when needed and maintain proper balance.
Smell alone isn’t a reliable indicator so always rely on proper water testing.

Featured Testimonial

First of all - a big thank you to Aaron from Sydney for your kind words:

"Ordered and delivered within 3 days. Happy with the service."

We genuinely appreciate you taking the time to leave feedback. Fast dispatch, reliable delivery and great service are what we aim for every single day at AquaTune. When customers like you notice - it means a lot.

Now, let’s dive into your excellent question.

Featured Question

“I'm always in the belief that if you can smell the chemicals then you're probably using too much. Is this accurate?”

Short answer: Not necessarily and often the opposite is true.

This is one of the most common pool and spa myths we hear.

Why You Smell “Chlorine”

That strong “chlorine smell” people associate with pools isn’t actually from too much chlorine.

It’s usually caused by chloramines.

Chloramines form when free chlorine reacts with:

Sweat
Body oils
Sunscreen
Urine
Organic debris

When chlorine combines with contaminants, it becomes combined chlorine (chloramines). These are:

Less effective sanitisers
Responsible for the strong smell
Often linked to eye and skin irritation

So ironically…

If you can strongly smell chlorine, it often means you don’t have enough effective free chlorine.

The Science (Made Simple)

There are two main types of chlorine in your pool or spa:

1. Free Chlorine

This is the good stuff.

It actively sanitises and kills bacteria.

2. Combined Chlorine (Chloramines)

This is “used up” chlorine.

It smells stronger and doesn’t sanitise effectively.

When free chlorine levels are too low:

It can’t properly oxidise contaminants.
Chloramines build up.
The smell increases.

So What Should You Do?

If your pool or spa smells strongly:

Test Your Water

Check:

Free Chlorine
Combined Chlorine
pH
Total Alkalinity

Home testing generally would require a commercial test strip. Otherwise, when you get your next water test done, ask what the combined chlorine reading is (the difference between Free and Total Chlorine). If it is more than 1 part per million, you need to shock the water.

Some Recommended Products For Testing Your Water

Shock The Pool Or Spa

A proper shock treatment (oxidising dose of chlorine) breaks apart chloramines and restores clean, effective sanitising power.

Maintain Correct Levels

Recommended levels:

Pool free chlorine: 1–3 ppm
Spa free chlorine: 3–5 ppm
pH: 7.2–7.6

Keeping your water balanced prevents chloramines from building up in the first place.

Recommended Collection: Chlorine Shock Or Boost https://www.aquatune.net.au/collections/chlorine-shock-or-boost

When Is It Too Much Chlorine?

Yes, you can over-chlorinate.

Signs of genuinely high chlorine levels:

Very high test reading (above 5–10 ppm depending on application)
Fading swimsuits
Strong chemical irritation
Bleached pool covers

But smell alone is not a reliable indicator.

The Real Takeaway

A strong chlorine smell usually means:

Not enough effective sanitiser
Chloramines have built up
The pool needs oxidation

Not that you’re “using too much”.

Thanks Again, Aaron

We appreciate your support and your thoughtful question. Helping pool and spa owners understand their water chemistry is part of what we do because clear water isn’t just about products, it’s about knowledge.

If anyone else has questions about pool or spa chemistry, feel free to contact us. Clean, balanced water = safer swimming and longer-lasting equipment.

And Aaron — enjoy the crystal-clear water in Sydney!

The AquaTune Team

P.S. Do you have a question about your pool and or spa? Share it with us here and as a small token of our appreciation we will also send you a discount code for $10 off your next order over $75 (which includes free delivery)... https://www.aquatune.net.au/pages/quick-favour

P.P.S. Do you look after your pool or spa yourself? Join our Do-It-Yourself Pool and Spa Maintenance community here… https://www.aquatune.net.au/pages/diy