Why Does My Pool Smell Like Chlorine?Updated a month ago

A strong chlorine smell doesn’t mean your pool is clean—it’s a red flag for chloramines, chemicals formed when chlorine reacts with sweat, oils, or urine. Here’s how to fix the stench and restore fresh, safe water.

Why It Happens

• Chloramines: When free chlorine bonds with contaminants, it creates smelly, irritating chloramines.

• Low free chlorine: Chlorine is "used up" fighting organics, leaving chloramines behind.

• High pH: Chlorine works poorly above pH 7.8, allowing contaminants to linger.

Step-by-Step Fix

1. Test Water: Use a reliable pool test strip to get accurate results.

   • Free chlorine: Should be 1–3 ppm.

   • Combined chlorine: Should be <0.5 ppm (if higher, shock the pool).

   • pH: Adjust to 7.2–7.6.

2. Shock the Pool:

   • Use chlorine shock (calcium hypochlorite or liquid chlorine) at 10x the combined chlorine level (e.g., if combined chlorine is 1 ppm, add 10 ppm). DO NOT USE STABILISED CHLORINE

   • Run the pump overnight to circulate.

   • Alternative: Use a non-chlorine oxidiser to remove chloramines 

3. Scrub & Clean:

   • Brush walls/floors to dislodge biofilm (chloramines cling to surfaces).

   • Clean filters and backwash if needed.

4. Replenish Chlorine:

   • Maintain 1–3 ppm free chlorine after shocking.

Prevention Tips for Aussie Pools

• Shower before swimming: Reduces oils and lotions entering the water.

• Test daily in summer: Heat and UV burn off chlorine faster.

• Use enzyme treatments: Break down organic waste before chlorine reacts.

• Cover the pool: Blocks debris and reduces chemical loss.

Final Tip: A well-balanced pool shouldn’t smell! If you detect that “chlorine” odour, it’s time to shock, scrub, and rebalance. 

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