There’s no practical reason why you can’t properly maintain the water quality of your pool or spa without hiring a professional service provider.Yes, it’s a chore, but fundamentally it’s not so different from other household tasks, like vacuuming or doing laundry: except, 
of course, that maintaining pool water requires a basic understanding of chemistry.
Even professional pool and spa service technicians would agree that, for the most part, homeowners are not only capable of maintaining the water quality of their backyard amenities on their own, but also are the best choice to do so. Simply, you live with your pool or spa every day, and therefore have the best access to it and ability to monitor and adjust, as necessary, the quality of the water.
At some point, perhaps on a regular schedule, you’ll want or need to consult with a professional pool and spa expert to solve particularly troublesome problems, conduct a annual or seasonal checkup of the entire system, verify your water quality tests and chemical values, and become better educated about maintaining your pool or spa. In fact, that’s how smart pool and spa owners protect the value of their investment and offer the safest, healthiest experience possible for family, friends, and neighbors.
In this chapter, you’ll get the basics of water quality and how (and why) to maintain the proper balance of the various elements in your pool or spa that contribute to its quality, from pH to the sun’s ultraviolet rays. You’ll also gain knowledge about sanitation, arguably the most important aspect of pool and spa water quality. Though certainly not mutually exclusive from the water’s level of acidity, hardness, or dissolved solids (all of which and more are explained in this chapter), a sanitizer such as chlorine is the critical element to maintaining healthy water for soaking or swimming.
There is a bit of chemistry-speak involved, but mostly about how assorted chemicals affect water quality, how to test for their presence and adjust them properly and in what order (yes, that matters), and the options that exist among them in terms of their performance, delivery into the water, and safe handling. There’s also a troubleshooting guide that identifies common pool and spa water quality problems and offers advice about how to solve them.
Like umpires and referees in sports, the quality of your pool and spa water ideally should be virtually unnoticed by swimmers and soakers, allowing them to enjoy the experience without oily skin, bloodshot eyes, or distracting odors-or perhaps worse health hazards. Maintaining balanced, healthy water in your pool or spa is a chore, but one at which you can quickly become proficient and easily work into your normal household routine.
When it comes to the quality of the water in your pool or spa, look and feel go a long way-if not all the way-as reliable indicators. 
If you can see whether a quarter is lying heads or tails at the bottom of the deep end of a pool, chances are pretty good that the water is healthy and in proper balance; if after a soak or a swim your skin feels clean rather than filmy or with a slight burning sensation, the water quality is probably well maintained.
Even so, visual and sensual tests are inherently subjective and inexact. A pool or spa can appear clear for some time, for instance, while its chemical content gets increasingly out of whack, until one day the water is cloudy and discolored and you notice the pool’s surfaces are stained or etched. A spa or hot tub might be seem to support a nightly routine of relaxation until its neglected and overburdened filtration system fails.
The lesson is that ideal water quality, in proper balance and with all of the elements within their respective recommended ranges, requires regular monitoring and adjustment even if everything looks okay from the deck or feels right in the water.
Keys to Pool and Spa water Quality:
• Maintain proper water filtration .
• Devise and follow a schedule to test for and balance chemical elements in the water.
• Clean the pool thoroughly after each use.
• Keep the pool or spa covered when not in use.
• Closely follow the directions of use for each chemical.
• Properly dispose of chemicals that have reached their expiration dates.
Cover your pool or spa whenever practical to minimize evaporation, preserving the water quality and the balance of sanitizing chemicals.
Leaves and other organic matter that pollute your pool or spa water begin to decompose and release chemicals almost immediately. Careful policing of the pool area and collecting debris supports healthy water.
Exposure to the elements is tough to avoid with an outdoor pool or spa, so it pays to learn how influences such as sun, wind, rainwater and organic matter affect water quality.
Clean, healthy water is essential to clean, healthy fun in a pool or spa.
Ideal water quality is a balance among a variety of elements and chemicals, each of which impacts the other; boosting one to bring it into its recommended range can push another out of its suggested scale. Knowing those consequences, and tips for achieving balance, are discussed later in this chapter. For now, here’s a primer of what contributes to the quality of your pool and spa water.
Sanitizers
Whether it’s chlorine, bromine, or some other chemical or method, the purpose of any sanitizer is to kill bacteria and other waste materials in the water and to control algae growth. A sanitizer mixes with oxygen in the water to dissolve, or oxidize, bacteria and algae-in effect, both killing and removing organic matter. What’s left over after the bacteria is eliminated is called the residual, the amount of which also needs to be monitored and kept within a recommended range to prevent new bacterial growth and help maintain sanitary water.
Stabilizers
To be effective over a longer period of time, chlorine sanitizers require a stabilizing agent. Cyanuric acid is a common stabilizer for chlorine, shielding it from the sun’s ultraviolet (UV) rays and also slowing the water’s rate of total dissolved solids pH. The level of pH in the water indicates its acidity; the lower the pH reading, the higher the acid content. Extremely or chronically acidic water is corrosive, eating away at any metal components and most surfaces, including plaster, tile grout, and vinyl liners; it’s also what causes your eyes to sting when you’re swimming. Conversely, water that is allowed to remain too alkaline (or too low in acid content) leaves calcium deposits on pool and spa surfaces and inside the plumbing system and equipment components. In addition to these reasons, it is important to keep the pH level within the recommended range to help optimize the effectiveness of your sanitizer.
Recommended Ranges
Experts, including health officials, generally agree on the respective levels of various elements that render pool or spa water healthy, as indicated below.
Element Recommended Level
pH 7.2 – 7.6
Total alkalinity 80 – 120 parts per million (ppm)
Cyanuric acid (chlorine stabilizer) 40 – 70 ppm
Chlorine residual (stabilized chlorine) 1.0 – 3.0 ppm
Calcium hardness 200 – 400 ppm
Total dissolved solids (TDS) less than 2000 ppm
Chlorine (unstabilized) 0.3 – 1.0 ppm
Total alkalinity. While pH measures the relative acidity of the water, total alkalinity indicates the amount of alkaline material present. The proper amount of total alkaline helps resist sudden or extreme changes in the water’s pH level by neutralizing or mitigating the effect of high levels of acid present in the water. Knowing your water’s total alkalinity tells you exactly how much acid or alkaline to add to the water to achieve the recommended pH level.
Hardness. All water, even treated, potable drinking water, contains minerals, or alkalines. The amount of one such mineral-calcium-determines the hardness of the water. In plaster-lined pools, calcium slowly leeches from the plaster into the water, adding to its alkalinity, and thus its hardness. If the water is too hard, it can raise the pH level above the recommended range and form white, salty deposits on the pool’s surface, usually at the waterline. Hard water can also be somewhat abrasive to your skin, while extremely soft water might leave a filmy substance.
Total dissolved solids (TDS). While hardness measures one mineral (calcium), the level of total dissolved solids in your pool or spa water accounts for the accumulation of all such content that has not been filtered out of the water. In addition to calcium, TDS includes chlorine, dirt and debris, exfoliation, cyan urate (a byproduct of cyanuric acid), perspiration, and other chemicals and elements present, in dissolved form, in the water; most TDS content, in fact, comes from the people using the pool or spa. In addition, the process of natural evaporation removes only pure water from a pool or spa, leaving dissolved solids behind and in relatively higher content due to the overall reduction in water volume. Total dissolved solids absorb the water quality chemicals you put into the water, rendering them less effective toward achieving proper balance and sanitation.
Climate. Factors including temperature (of both the outdoors and the water), relative humidity, sun exposure, wind, and rain all contribute to the quality and balance of pool or spa water. Sustained high temperature and sun exposure, for instance, promote algae growth in shallow areas of the pool; wind across the surface of the water not only speeds evaporation and deposits dirt, leaves, and other debris into the water (thus absorbing sanitizers and boosting total dissolved solid content), but also can carry and deposit algae spores. Rain into an open pool or spa quickly destabilizes your careful balancing act of all the elements.
Bather load. The contributions to total dissolved solids and other elements that can throw water quality out of balance and make it more difficult to achieve are most often the result of heavy pool or spa use. We humans carry with us, and unload, a lot of “baggage” when we swim or soak, including sweat, sunscreen, dead skin, hair, and other unseemly content. That’s why it helps to install a shower on or near the pool deck and insist on its use before people use the pool or spa. Regardless, you’ll need to calculate bather load (or use) to have any hope of achieving proper water quality and balance.
Chloramines. That smell coming off the pool water that most people associate with too much chlorine is, in fact, just the opposite. When a chloride sanitizer combines with naturally occurring ammonia and other nitrogen compounds in the water, it creates chloramines, rendering an often offensive, bleach like odor. If that smells like your pool or spa, it may be time to shock, or “superchlorinate” the water, an extreme (but safe) balancing technique detailed later in this chapter.
New products that help maintain water balance include this capsule containing an odorless, tasteless oil that is distributed into the pool water through the skimmer. The oil floats on top of the water and forms a micro-thin skin that reduces evaporation and chemical loss.
