By Scott Newton
Let’s begin with the fact that great drinking water and just great water are very different from great swimming pool water. They vary with respect to pH levels, free chorine levels, total alkalinity, calcium hardness and cyanuric acid.
Water variations
Unlike drinking water, perfect pool water has an acceptable pH range of 7.2 to 7.6 (pH is a number that characterizes the acidic or basic attributes of a liquid substance and is measured on a scale of 0 to 14). pH is considered one of the primary indicators of balanced water. The pH of normal drinking water ranges from 6.5 to 8.5.
Extremes in pH, high or low, will cause irritated skin and eyes. The pool water will have a tendency to form scale in the plumbing as it will in drinking water. The hypochlorous acid/free chlorine (i.e. the aggressive disinfectant formed by the combination of chlorine and water) will be less active.
Low pH will corrode equipment and cause the hypochlorous acid to be used up too quickly. Total alkalinity is the measure of the water’s ability to resist pH change. If total alkalinity is low the pH will bounce around dramatically, making it difficult to keep the water clear and comfortable. If the pH drops below 4.5, total alkalinity is destroyed. If alkalinity is too high, the pH will also be high (and difficult to bring down) along with the problems of cloudy water, dry skin, scale formation and inactive chlorine.
Calcium hardness in pool water is an important water balance characteristic. Water that has too little calcium is likely to “look” for its missing nutrients, often resulting in copper corrosion and etching of pool surfaces. When water has too much calcium, the water will expel unwanted calcium out of the solution, forming scale on the plumbing more readily.
Cyanuric acid (also referred to as a stabilizer/conditioner) protects hypochlorous acid from being lost to the ultraviolet (UV) rays of the sun. HOCl is catalyzed by UV rays that results in both chloride and hydroxide ions. When a hypochlorous acid molecule is attached to a molecule of cyanuric acid, it is safe from the UV rays. However, while attached to the stabilizer, the hypochlorus acid does not kill bacteria. Hypochlorous acid only works when it’s moving between stabilizer molecules. The maximum cyanuric acid level allowed in commercial swimming pools is a parameter established by each local health department.
Five key steps
In noting some of the water balance parameter differences between drinking water and pool water, it’s also important to note that unlike the first two types of water, swimming pool water is maintained on a closed system that reuses water.
Most common pool care problems can be avoided or at least minimized by remembering these five keys:
- Circulation—The more the water moves, the harder it is for problems to take hold. Properly circulated water ensures that chemicals are properly mixed throughout the pool.
- Filtration—A filter removes particles that can cloud the water and compete with bacteria and algae for the sanitizer’s attention.
- Cleaning—Vacuuming and brushing debris and biofilm on the pool surfaces prevent the growth of bigger problems, making it easier to keep the water clean. Routine use of a skimmer net is helpful in removing floating debris to prevent it from settling to the bottom of the pool.
- Chemistry—Adding the proper amount of the right products at the correct time ensures that the water stays clear, clean and at its best for swimming.
- Testing—By measuring critical water factors, the water must be balanced while maintaining an adequate sanitizer level to avoid costly correction later.
Getting started
Pool water has chemical traits that must be measured regularly. According to a recent survey, the No. 1 service request from pool owners is with respect to identifying quick and convenient water testing facilities and being able to speak to an expert about a customized program to maintain great pool water.
Maintaining clean, sparkling pool water is not only important for day-to-day enjoyment, but it’s also a major factor in the life of the pool. Weekly water analyses are very important in protecting a pool from uncontrolled bacteria and/or algae growth as well as maintaining clear, sparkling inviting water that is comfortable to the eyes and skin.
One will want to consider using a system that is convenient and simple, taking just moments a week. But first take a sample of water to the local pool and spa dealer for a free water analysis.
Proper water testing
Some pool and spa chemical manufacturers have developed revolutionary technology that performs water analysis on site in just a matter of minutes. These tests were derived from the high tech world of medical testing to create a cutting edge solution for pool and spa water analysis. The newest systems are available at a local pool and spa care center and are easier and more accurate than previous procedures. By using technology originally developed for the medical monitoring and diagnostic industry, this new system reads a special dip-and-read test strip to provide readings for free chlorine residual, total chlorine residual, bromine residual, total alkalinity, borates, calcium hardness, cyanuric acid, biguanide and hydrogen peroxide—all with unparalleled accuracy.
The secret of this test’s proficiency rests in the state of the art technology, which detects small changes in readings and registers certain colors that are masked by, or blended with, other colors invisible to the human eye. The system ensures the consistency of testing techniques and readings from employee to employee and greatly reduces the risk of misreads.
Another key benefit of this testing system is speed. Including all data input, halogenated or biguanide-treated (non-halogenated) pool water can be tested in two minutes or less.
While using this system is incredibly simple, the technology behind it is highly advanced. Specifically, the system uses an incandescent lamp and a photodiode to read reflected light back from a fixed read area, which is simply a pad on a test strip. Next, the photodiode converts the light reflection into electrical impulses, which are processed and converted into usable information. This eliminates human error due to perception of color and testing technique. Input errors are also less likely because all results are automatically downloaded into the appropriate data field.
The combination of a test strip and other analyses will provide local pool and spa care professionals with the most powerful and innovative information database and pool maintenance system available.
The three-step program
Pool owners look for maintenance programs that will provide great results without taking up a lot of their free time. One highly effective maintenance program involves a three-step procedure that is performed once a week.
The first step requires the use of a unique continuous sanitizer that contains a built in sunscreen to prevent chlorine residual from dissipating too quickly. This product is much easier on pool equipment than other sanitizing products, because it virtually stops dissolving when the pool pump is switched off. This prevents both free chlorine buildup as well as pH depression.
Step two uses oxidizers/clarifiers to keep water sparking clear. The applied oxidizers/clarifiers remove undesirable compounds and work in all pool types easily and effectively.
Step three prevents all types of algae from growing in pool water. This algae inhibitor, which works with the sanitizer, requires no mixing or pre-dissolving and is effective for all types of pools.
The advanced technology of the weekly three-step program makes, clean, sparkling pool water as easy as one…two…three!
Conclusion
Knowing the basics in maintaining perfect pool water balance will allow proper preparation of a pool when next summer arrives. Rest assured, employing these methods will add life and enhanced performance to equipment for clear, brilliant and comfortable pool water.
About the author
Scott Newton is director of marketing for BioGuard®, a division of BioLab, Inc. With headquarters in Decatur, Ga., BioGuard Inc. is one of the world’s largest specialty retailers of pool and spa chemicals. The company’s comprehensive line of swimming pool and spa products includes sanitizers, oxidizers, balancers, algicides, winterizers and other specialty products for residential, service and commercial markets. For more information, visit the website at http://www.bioguard.com.