It’s Science! Sanitizers and Your Pool

ORGANIC – NATURAL – CHEMICAL-FREE: These terms describe the ideal when it comes to food and drink. None of the sane among us want weird hormones and bathroom disinfectant ingredients inside our bodies. But how does this relate to the waters in which we swim?  Can we not just create a little cement lake or salt water habitat in our backyards and swim as nature intended?

Sanitized vs. Organic Water

Swimming in nature is a fun adventure, and under the right conditions is mostly safe and healthy.  Flowing rivers, ocean waves, and lake swimming holes provide bathing spots whose water is refreshed naturally and constantly. Swamps and stagnant ponds, however, pose health and safety hazards; the instinctive human inclination is to avoid them.

Pools and spas, if not kept with proper chemistry and sanitization, become the latter. Even though the water is sent through the filtration system with a regular turnover rate (how frequently all of a pool’s water is sent through a filter) and adequate circulation, the lack or imbalance of certain, necessary chemicals can turn any pool into a green, unhealthy mess. Organic materials from leaves to pollen to runoff during rains get in the pool and are not washed away anywhere. They recirculate with the self-contained pool water along with bacteria and other organisms too microscopic to be filtered out. Pool water must have a consistent, minimum level of sanitizer and must be refreshed periodically in order for it to be deemed safe for bathing.

What is this…sanitizer?

There is a minimal variety of pool water sanitizers, and many of these are to be used as supplements to the main sanitizer: chlorine. I understand some of you may have just turned your nose up in disgust, but chlorine is the primary means of sterilizing and purifying pool water. Even salt water systems, which are the latest in comfortable, healthy swimming trends, produce chlorine by a process I will explain in the following crude and general steps:

  • Salt is added to the water at a rate of + or – 3,000 parts per million (PPM)
  • Different sensors monitor flow, temperature, and salinity
  • An intricate system of electronics converts alternating current (AC) to direct current (DC) voltage
  • The DC moves back and forth from titanium plates in a salt cell to the electronics system
  • The DC energizes the titanium plates, which break down salt molecules as they pass through – NaCl becomes separate Na (sodium) and Cl (chlorine) ions
  • The chlorine is free to kill bacteria and organic material (to sanitize)

The chlorine feed from a salt chlorine generator can typically be regulated, but the intent is to use salt water (which is comfortable for swimming) to produce chlorine (which is necessary for a healthy swimming environment).

Di-chlor and tri-chlor tabs are some forms of chlorine that can be placed in any of a variety of dispensers and dissolve. They contain a stabilizer (cyanuric acid) that is meant to keep chlorine from dissipating easily in sunny conditions.

Calcium hypochlorite is also known as granular chlorine. This is often used to “shock” or hyper-chlorinate your pool as needed. It also serves as a way to prepare for or deal with the aftermath of an influx of organic materials, such as tons of leaves falling or a rain event.

Bromine is another type of sanitizer that works like chlorine. It is typically meant for small bodies of water, particularly indoor pools or spas.

Some supplemental sanitizers used occasionally in residential pools include UV, low-end ozone, ionic, and mineral sanitizers. These cannot work apart from chlorine or bromine because their effectiveness is temporary and depends on how long the filter pump circulates. Mineral sanitizers contain elements that work only in conjunction with chlorine to reduce the need for as much free available chlorine in the water.

Should I Just Throw Some Shock in It?

As important as sanitization is, equally important is the chemical balance of the water. Water wants to be satisfied with its chemical make-up. Too little or too much of the following 4 chemical factors can cause the water in a pool to either rob from its environment or deposit scale onto its surroundings:

  • Total dissolved solids (TDS)
  • Calcium hardness (CH)
  • Total alkalinity (TA)
  • Power of Hydrogen (pH).

Temperature is a fifth factor in this “saturation index”; adjustments to the other four must be considered depending on water temperature. Warmer water tends to be more scaling (oversaturated) than cooler water.

Any homeowner can test for chlorine, CH, TA, and pH with a 4-in-1 test kit, and should do so regularly in the absence of a full-service cleaning company. Specialized equipment is needed to test for TDS and other crucial elements in the water, such as phosphates (algae food), metals, and stabilizer. This equipment can also tell you whether your water chemistry (1) needs any of the 4 chemical factors and will rob from plaster and other parts of the pool structure or (2) has too much of any of the 4 chemical factors and will deposit scale onto surrounding surfaces.

Taking care of your pool is not as simple as throwing chlorine and baking soda in it, but neither is it rocket science. You can satisfy its chemical and sanitization needs with regular care, a user-friendly but thorough test kit, and the quarterly visit (at least) to a reputable pool water testing lab.  Not all retail shops are equally adept at water analysis; even some national franchises may have the proper equipment but no personnel with the proper knowledge to interpret findings. Feel free to call us or any reputable, full-service cleaning company you may know with questions or concerns. There is no need to be overwhelmed by pool maintenance; with enough information, you can handle any situation.

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