Chlorine is a standard component to any swimming pool maintenance program. This disinfecting agent sanitizes the water by killing contaminants such as human impurities, bacteria, viruses and algae. Sometimes, the chlorine dissipates, meaning there is a noticeable drop in chlorination levels. Several factors can cause this.
Chlorine levels in swimming pools need to be tested regularly by placing water drops into test tubes. Kits are available for these tests at pool supply dealers, or water samples may be taken directly to those same retailers for inspection. These tests will indicate the amount of free available chlorine (FAC), which is the chlorine in the pool that is still on hand and ready to kill bacteria. Tests also will show the combined available chlorine (CAC) that already has been used up fighting contaminants. The sum of FAC and CAC is the total chlorine level. When readings become low, the pool owner needs to determine the source of this dissipation.
Ultraviolet (UV) rays increase the rate that chlorine is consumed in the water. Therefore, chlorine dissipates more quickly on hot, sunny days. Pool care specialists recommend that chlorine be added to pool water in the evenings to safeguard against dissipation.
Pool water is contaminated when swimmers leave behind human secretions and excretions such as perspiration, urine and diarrhea. A high volume of pool visitors will cause chlorine levels to drop, as the chlorination unleashes its powerful cleansing properties.
Products containing cyanuric acid are routinely added to pool water to prevent chlorine from being dissipated from sunlight. Known as conditioners or stabilizers, cyanuric acid mixtures can become too high and thereby weaken the chlorine's strength. This is known as chlorine lock. A pool owner's warning sign of too much cyanuric acid is a minimal reading of chlorine--sometimes as low as zero--even though he has been adding the chlorine products for several days. The pool water might appear cloudy. Test strips will confirm excessive amounts of the cyanuric acid. Treatment of chlorine lock requires the pool to be partially drained and then refilled with fresh water.
Additional doses of chlorine may be warranted, especially when pool water has a strong odor of chlorine. Mixing a heavier quantity of chlorine than usual is known as "shock treatment" and can be necessary when chlorine dissipation is suspected. "Shock" is a quick way of ensuring that the appropriate amounts of chemicals are in place to attack any pollutants so that swimmers don't become ill.
- Swimming Pool Maintenance Tips: Can't Keep Chlorine Level Up in the Swimming Pool?
- American Chemistry: Pool Treatment 101: Introduction to Chlorine Sanitizing
- North Carolina Department of Environment and Natural Resources: Water Chemistry for Swimming Pools
- Real Estate Pro Articles: Enjoy Fun, Health, Happy Summers: Home Pool Care Information
- Photo Credit bonde, james bonde (le retour) image by Patrick LAFITTE from Fotolia.com
Why Is the Chlorine Level Low in My Pool?
Maintaining a minimum level of chlorine in your pool or spa is important for keeping the water clear, discouraging algae growth and...
Health Effects of High Chlorine in Swimming Pools
Most regular swimmers know that high chlorine content in swimming pools causes health problems such as skin and eye irritation. But it...
What Is the Safe Level of Chlorine in Drinking Water?
Up to 98 percent of water treatment facilities in the United States use some form of chlorination process to clean their drinking...
How to Diagnose Chlorine Lock in a Swimming Pool
While swimming pool chemicals help maintain the quality of your water, they occasionally contribute to problems. Chlorine lock results when insufficient water...
How to Keep Chlorine Levels Up in a Pool
Pools use chlorine to kill algae, bacteria, and other organisms that live in the water to keep them clean. The chlorine acts...
How to Remove Chlorine From a Pool
Chlorine is a chemical used in most swimming pools to disinfect the water. Unfortunately, prolonged exposure to strong doses of the chemical...
Troubleshooting a Pool That Eats Chlorine
It's important to maintain the right level of chlorine to prevent the growth of bacteria and algae in a pool. Unfortunately, chlorine...
Does the Heat & Sun Affect Pool Chlorine?
Swimming pools usually require specially formulated types of chlorine to keep their water free of hazardous bacteria. The most common form of...
Chlorine Levels in Pool Are Too High
There are a number of issues that can confront the owner of a swimming pool when it comes to her pool. One...
What Causes Free Chlorine to Be Low in a Saltwater Pool?
A saltwater pool works with a chlorine generator to provide the required chlorine to disinfect the pool. Just like in a chemical pool, there...