Combined Chlorine The amount of chlorine that has combined with other compounds is measured as combined chlorine. When chlorine in pool water reacts with organic material like skin oils, urine, or sweat, combined chlorine, also known as chloramines, is formed.
Despite the fact that chloramines are only one type of molecule, we refer to all of them as such. Pool water contains combined chlorine, which causes a terrible “chlorine” odor, burning eyes, and irritated skin. You can remove combined chlorine in your pool through chlorine or non-chlorine shock.
How to detect if your pool has high combined chlorine levels
Many people believe that they can smell or “feel” when their pool has too much chlorine, but the only way to know for sure is to conduct a test. If your pool is left uncovered for long periods of time, you should test the chlorine level at least once a day.
However, chlorine tests are simple to conduct. Many companies produce test strips that take only a few minutes to complete. Other test strips that can measure total chlorine and free chlorine levels are also available.
Tips to reduce combined chlorine in pool water:
If the chlorine level in your pool is too high, you must treat the chemicals in your pool. To begin, you must first decide the scale on which your levels will be measured.
If your levels are only slightly elevated, you should avoid using the pool for around an hour. This period of inactivity is usually enough to bring your levels back into the right range. Note: If your chlorine level is extremely high, however, you’ll need to do a little more.
In this article, we will discuss two general methods to reduce combined chlorine: chemically and naturally.
How to reduce combined chlorine chemically
Super chlorination is by far the most widely used and accepted method of dealing with combined chlorine. It involves dumping an excess of free chlorine into the pool (the industry standard is 10x the level of combined chlorine, which is more than enough).
The oxidant demand should be destroyed by this surge of oxidizing power. It also kills almost everything that might be in the water, which is a plus. The disadvantage is that the pool must be closed for superchlorination, and once completed, the Free Available Chlorine Level (FAC) must be brought back down or allowed to drop naturally.
Super chlorination is the rocket boost that finally pushes past the demand, achieving and exceeding the breakpoint, and building free chlorine residual in the breakpoint chlorination process.
Non-chlorine shock needs to add more oxidizer to the water, but in a non-chlorine form. Potassium monopersulfate is the most commonly used chemical. It can help with oxidants but has no sanitizing qualities.
Enzymes do not reduce combined chlorine directly, but they do supplement chlorine against non-living organic bather waste. Carbon-based body products such as body oils, deodorants, cosmetics, lotions, and sunscreen are metabolized by enzymes. As a result, chlorine has less to oxidize.
In the fight against nitrogen compounds, less oxidant demand means more chlorine. While enzymes such as CV-600 do not directly address nitrogen compounds such as ammonia and urea, they can significantly improve chlorine efficiency.
Hydrogen peroxide is a potent oxidant that produces water and oxygen when it combines with chlorine. If you notice little effervescent bubbles in the pool, it’s functioning.
Use hydrogen peroxide designed for pools for the best results. This product contains a higher concentration of hydrogen peroxide than the cleaning products for your home.
At pH values higher than 7.0, hydrogen peroxide is most effective. Test the pH of the pool and adjust the levels before using this product to ensure that the hydrogen peroxide effectively reduces extra chlorine.
Other chemicals have been examined, but they are not yet confirmed safe for use in swimming pools. One of them is chlorine dioxide, which is a particularly potent type of chlorine that can easily remove chloramines. It is not currently used in commercial pools, but it is widely used in other industries.
How to reduce combined chlorine naturally
Replacing the Existing Water
Another option is to dilute your pool water, but this takes time. Refilling your pool can also cause pH (potential of hydrogen), alkalinity, calcium hardness, and other chemical levels to fluctuate. However, if you go this route, make sure to test all of your levels to get the best results.
What happens if combined chlorine is high?
Since the combined chlorine is any chlorine molecule that has reacted with other organic compounds, it means that the chlorine molecule is no longer active to disinfect effectively.
So, having a high level of combined chlorine in your pool means that the chlorine sanitizer is no longer active. This makes your pool a breeding space for microbes. Algae and other contaminants can easily invade your pool and cause infection.
Moreover, your pool can easily turn green due to algae blooms. Nonetheless, it can also make your pool cloudy. If these issues are not addressed, they can lead to pool maintenance challenges.
However, make sure the chlorine level in your pool is not too high. Having a high chlorine level can also be detrimental to your health and the pool as well.
It’s dangerous to have too much chlorine in your pool water. High levels of chlorine can damage lung tissue, cause skin and eye damage, and trigger asthma. Not only is it hazardous for your health, but excess chlorine can also be detrimental to your pool.
High chlorine levels lower the pH of your pool’s water, making it more acidic. The higher the acidity of the water, the higher the chance of corrosion. Corrosion can harm metal piping, equipment, and your pool’s surface (tiles, liners, concrete, etc.). It can also damage pool accessories and anything else that comes into contact with the water in your pool.
Why is my total chlorine high but free chlorine low?
An excessive amount of pool stabilizer in the water can cause chlorine to become locked up, or chemically bound up. It’s possible that too much stabilizer was used. This might occur if the pool water hasn’t been partially drained and replenished. A pH (potential hydrogen) imbalance could also cause chlorine to be locked up.
Furthermore, the high level of combined chlorine in your pool makes the free chlorine low. Remember that the total chlorine is the sum of free chlorine and combined chlorine. So, if the level of combined chlorine increases, it will affect the level of free chlorine present in the pool.
What is the difference between free and combined chlorine?
Free Chlorine
The type of chlorine that is commonly tested to determine proper chlorine levels in pool water is free chlorine—this is the amount of chlorine that is still available to sanitize your water. The term “free chlorine” refers to chlorinated water that has not been contaminated.
Use a FAS-DPD test kit to properly measure free chlorine in your pool and ensure that it is between 1.0 and 3.0 parts per million (ppm). Maintaining these levels will ensure that your pool water is of the highest quality.
Combined Chlorine
Combined chlorine is the chlorine that has already been “reduced” in your water to sanitize it. When chlorine in pool water reacts with organic material like skin oils, urine, or sweat, combined chlorine, also known as chloramines, is formed. Pool water contains combined chlorine, which causes a terrible “chlorine” odor, burning eyes, and irritated skin.
What is an unsafe level of chlorine in a pool?
Always maintain a range between 1 ppm and 4 ppm. Anything beyond 5 ppm is not safe for your health. The presence of chloramine or too much chlorine in a pool can cause a variety of health issues. Here are the warning signs and symptoms of swimming in a pool with too much chlorine (or not enough chlorine)—and how you can test the waters (literally) to stay safe:
Irritated, red eyes
According to Dr. Uren, because chloramine is heavier than air, it floats at the pool’s surface. It can sting your eyes if this gets into them. It smells particularly strongly in your nose.
Dry Hair, skin, and nails
“Those who swim regularly and for long periods of time may experience dryness and irritation from the chlorine.”
Poisoning with Chlorine
- Blurred vision
- Red and blistered skin
- A burning sensation in the nose, throat, and eyes are burning.
- Blurred vision
Getting some fresh air and rinsing your eyes (if affected) with plain water for 10 to 15 minutes can help, but if symptoms persist or worsen, consult a doctor.
Is combined chlorine and total chlorine the same?
You’ve probably heard terms like “free chlorine” and “combined chlorine.” Let’s see if we can figure out what they mean.
FAC (Free Available Chlorine): This is the type of chlorine that you test in your pool for. Free chlorine is unused and available, floating around like invisible magic dust, ready to sanitize your swimming pool water.
Combined Available Chlorine (CAC): This is the chlorine that has already sanitized your pool and is no longer needed. It’s worn out, overworked, and reduced, but it still matters… and remains in your pool. Waiting.
Total Chlorine (TC): Is the sum of the two: free chlorine plus combined chlorine equals total chlorine.
How long should you run filter after shocking pool?
While shocking your pool will help kill any germs or algae, it will not completely remove them; you’ll need your filter for that. So make sure your pool filter is running for at least 24 hours.
How long does it take for shock to clear water?
When the chlorine level has dropped to 5 ppm or less, which is considered safe for swimming, Before going for a swim, test the water to make sure the chlorine levels aren’t too high. Heavy granular chlorine shocks usually take 24-48 hours to work.
How do you stop chlorine locking?
Drain your pool partially.
If your pool’s chlorine lock is caused by too much cyanuric acid, the easiest way to rectify it is to drain it partially. You can also use a neutralizer to remove the excess cyanuric acid in the pool. You can get the chemicals from pool stores.
What is the maximum allowable level of combined chlorine?
According to PWTAG, the combined chlorine level should not exceed 1 mg/l. However, it does not currently recommend that a pool be shut down if that level is exceeded. However, always target 0.5 ppm or less.
Can you swim in a pool with high chlorine?
No. High levels of chlorine can irritate the lungs, cause skin and eye damage, and trigger asthma. Not only is it bad for your health, but the increased chlorine can also be bad for your pool.
What causes high combined chlorine in pool?
When chlorine in pool water reacts with organic material like skin oils, urine, or sweat, combined chlorine, also known as chloramines, is formed. Pool water contains combined chlorine, which causes a bad “chlorine” odor, red eyes, and irritated skin.
How do I lower the combined chlorine in my pool?
- You can lower the combined chlorine through chlorine or non-chlorine shock.
- It warms the pool water.
- Dilute the pool.
