THE strong smell of chlorine at a pool, while offensive to the nostrils, is usually seen as a sign that the water is going to be very clean.

But there’s actually a grim reason why some swimming pools smell stronger than others.

This is because the stronger the smell of chlorine, the dirtier the water in the pool is - and someone may well have peed in there.

Chlorine works by releasing two chemicals that destroy germs in the water.

These chemicals are hypochlorous acid and hypochlorite ion.

The odour you smell isn’t actually the chlorine itself, but actually chemical compounds called chloramines.

According to the American Chemistry Council, chloramines build up when the water hasn’t been properly treated.

They result from a combination of chlorine with sweat, oil and urine in the swimming pool.

So to prevent pools getting too stinky, it recommends that "By showering before entering the pool, and washing these substances from the skin, swimmers can help minimise pool smell.”

So next time you see sign reminding you to shower before getting in the pool, it’s best not to ignore it as doing so will contribute to a build of chloramines in the pool.

The Council advises that while swimmers worry that they might get red eyes because there’s too much chlorine in the water, it’s actually the opposite.

It advised: “You may be surprised to learn that there is no odour to a well-managed pool."

It continued: "Chloramines, which produce pool smell, can be eliminated using chlorine.”

The Water Quality and Heath Council adds that while indoor pools may “emit a light chemical odour”, it is best to stay out of the water if there is a “strong chemical smell present”.

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