While a strong chlorine smell might seem like a sign that your pool is well-sanitized, it actually means the opposite. That sharp, chemical-like odor is often caused by chloramines, also known as combined chlorine, which form when chlorine reacts with contaminants in your pool water. In other words, if your pool smells strongly of chlorine, your sanitizer may be working overtime.
The good news? That “public-pool” chlorine smell is usually easy to fix once you know what’s causing it. Here’s what that smell really means, why it happens, and how to get your pool water back to clean, clear, and comfortable.
What Causes a Strong Chlorine Smell?
That strong “pool smell” is usually not from fresh, active chlorine, but rather from chloramines. Chloramines form when Free Chlorine, the working chlorine in your pool, interacts with nitrogen and ammonia compounds. These nitrogen and ammonia compounds come from various contaminants, such as:
- Sweat
- Sunscreen
- Body oils
- Lotions
- Dirt and debris
- Urine
- Leaves and organic waste
Your pool’s chlorine is supposed to kill bacteria and help keep the water clean. But when there’s too much organic waste in the water, chlorine gets used up trying to break it all down. As this happens, combined chlorine can build up and create that strong chemical smell. To understand how chloramines are formed, it helps to know the different types of chlorine in your pool:
- Free Available Chlorine: This is the active chlorine available to sanitize your pool.
- Combined Chlorine: This is chlorine that has already reacted with contaminants. It is less effective and can cause odor, eye irritation, and uncomfortable water.
Signs Your Pool Has Chloramines
A strong chlorine smell is the biggest clue, but it’s not the only one. You may also notice:
- Red or irritated eyes
- Itchy or dry skin after swimming
- Cloudy or dull water
- Low free chlorine levels
- Chlorine that disappears quickly
- Water that smells “chemical” or unpleasant
If your pool checks several of these boxes, chloramines are likely part of the problem.
How to Get Rid of Chlorine Smell in Your Pool
The best way to remove chlorine smell is to break down chloramines and restore proper water balance.
1. Test & Balance the Water
Start with a complete water test. Check your free chlorine, total chlorine, pH, alkalinity, cyanuric acid, calcium hardness, and other key levels. Your free chlorine and total chlorine readings can help determine if combined chlorine is present. If total chlorine is higher than free chlorine, combined chlorine may be building up.
Before shocking your pool, make sure your water is properly balanced. Pay close attention to pH and total alkalinity. If your pH is too high or too low, chlorine will not work as effectively. Balanced water helps your sanitizer do its job and makes your pool more comfortable for swimmers.
2. Shock the Pool
Shocking your pool helps break apart chloramines and remove the odor-causing contaminants in the water. If your Free Chlorine level is below 2 parts per million (ppm), use Power Powder Plus or Chlor Brite to superchlorinate the water, destroy chloramines, and bring the Free Chlorine level up.
When the Free Chlorine level is at or above 2 ppm, use a chlorine-free oxidizer like Fresh ‘N Clear to clear chloramines and non-living organic contaminants in the water. Always follow label directions and test your water before swimming again.
3. Run the Pump and Filter
After shocking the pool, run the pump and filter for at least 24 hours. This not only helps your filter trap the debris that’s causing your chlorine to get used up, but it also helps disperse the shock and other chemicals through the water faster.
4. Clean the Filter
Your filter plays a big role in removing contaminants from the water. If it’s dirty or clogged, it can’t do its job well. If your filter has not been cleaned or backwashed recently, this is the perfect time to give it attention. A clean filter can help prevent odors, cloudy water, and recurring water problems like algae.
How to Prevent Chlorine Smell From Coming Back
Once the smell is gone, the goal is to keep chloramines from building up again. Follow these steps to keep your pool looking, feeling, and most importantly, smelling its best.
Maintain a Consistent Weekly Routine
Regular maintenance helps prevent contaminants from overwhelming your chlorine. Test your water weekly, maintain proper sanitizer levels, brush and vacuum all surfaces, and shock or oxidize as needed.
DID YOU KNOW? Shocking weekly with Leslie’s Power Powder Plus shock can solve up to 90% of common pool problems! Adding Power Powder Plus into your weekly maintenance routine can make a huge difference in the health of your pool. Learn more in our blog article!
Shock After Heavy Pool Use or Storms
Pool parties, kids swimming all day, hot weather, and sunscreen-heavy swim sessions can quickly add organic waste to the water. Shocking after heavy use helps reset the water and keeps chlorine working efficiently.
Use a Weekly Oxidizer
A weekly oxidizer like Fresh ’N Clear helps break down swimmer waste, sunscreen, sweat, and body oils. This can reduce chlorine demand and help prevent that strong chemical smell from returning.
DID YOU KNOW? Leslie’s Fresh ‘N Clear eliminates non-living organic contaminants and boosts sanitizer efficiency by eliminating and preventing chloramines. Plus, with just a 15-minute wait time, it’s the ideal oxidizer for when your pool needs a quick pick-me-up. Learn more in this blog article!
Ask Swimmers to Rinse Off Before Swimming
It may not be the most glamorous pool care tip, but rinsing off before getting in the pool can make a big difference. Less sweat, sunscreen, and body oil in the water means less work for your chlorine and less chance of problems developing.
Keep Debris Out of the Pool
Leaves, grass, pollen, and other debris add organic material to the water. These contaminants make your chlorine work overtime, leading to chloramines, cloudy water, and algae. Skim regularly, brush pool surfaces, and empty baskets often to help reduce chlorine demand.
Can You Swim in a Pool That Smells Like Chlorine?
It depends on your water test results. A strong chlorine smell can mean combined chlorine is present, and the water may be irritating to eyes and skin. If your water smells harsh, looks cloudy, or causes discomfort, it’s best to test and treat the water before swimming.
Do not rely on smell alone. Always test your water to confirm sanitizer and other chemistry levels.
The Bottom Line
A strong chlorine smell does not usually mean your pool has too much chlorine. It often means your chlorine is reacting with contaminants and needs help. The fix is simple: test the water, balance it, shock or oxidize, circulate, and clean your filter. With the right routine, your pool can smell fresh, feel comfortable, and stay swim-ready all season long.
Need help figuring out what your pool needs? Bring a water sample to your local Leslie’s for a free water test and personalized treatment plan.
