pH

pH is a number that characterizes the acidic or basic characteristics of a liquid substance. Expressed as a number on a scale of 0-14, with 7.5 being neutral as far as pools are concerned; values less than 7.0 are acidic and values greater than 7.0 are basic. The acceptable pH range is 7.2-7.8. If pH is too high or too low, the water will feel uncomfortable to swimmers.

If pH is Too High…(above 7.8)

Contributors to high pH include rain, plaster surfaces, algae, and some pool chemicals. The water will be cloudy and swimmers will complain of dry skin and irritated eyes. The water will have a tendency to form scale in the plumbing and on the surfaces. The available chlorine will be less effective. Lo’N Slo can be used to lower a high pH level.

If pH is Too Low…(below 7.2)

Contributors to low pH include most rain, new vinyl liners, swimmers, and some chemicals. The water will be clear, but it will irritate the skin and make eyes red. It will also corrode equipment and the HOCL will be used up rapidly. Balance Pak 200 can be used to raise a low pH.

Total Alkalinity – the pH Buffer

Total Alkalinity is a measure of the ability of the water to resist pH change. With this test, we are measuring the concentration of carbonates, bicarbonates, silicates, borates and other chemical compounds that contribute to Total Alkalinity. The ideal range for Total Alkalinity is 80-120 ppm. If the Total Alkalinity of water is kept within its ideal range, it acts as a buffer against changes in pH.

If Total Alkalinity is Low…

The pH will bounce around dramatically, making it difficult to keep the water clear and comfortable. If the pH ever drops to 4.5 or below, all Total Alkalinity is destroyed. Balance Pak 100 can be used to raise the Total Alkalinity level.

If Total Alkalinity is High…

pH will also be high (and difficult to bring down) and you face the problems of cloudy water, dry skin, scale formation and inactive chlorine that come with having a high pH. To lower Total Alkalinity, apply muriatic acid in dosages over several days.

Hardness

Remember, water is the universal solvent. Given enough time, pressure and/or proper temperature, water will dissolve most metals or minerals into a solution. Because of this tendency, any minerals that are present in the water’s environment will ultimately end up dissolved in the water.

Hardness in pool and spa water is an important water balance characteristic. Water that has too little hardness is likely to be aggressive water. This aggressive nature is defined by the water’s need to satisfy its mineral appetite. If there are not enough minerals in solution to satisfy this appetite, the water will look for a way to satisfy its mineral hunger. The surface of plaster pools and spas is the most vulnerable to this aggressive search for mineral satisfaction so depending on the pool or spa surface, the hardness level is adjusted accordingly. The ideal range for plaster pools is 200-400 ppm. For all other pools it is 175-400.

If Hardness is High…

The water may have a tendency to form scale on surfaces, plumbing and equipment, especially if the water temperature is high. The only way to lower Hardness is to drain some of the water and add new source water. Scale Inhibitor can be added to control the formation of scale, but it will not lower the Hardness level.

If Hardness is Low…

The water will corrode pool equipment and plumbing and etch pool surfaces. This tendency is intensified if pH and Total Alkalinity are also low. Adding Balance Pak 300 will raise the Hardness level in a pool.

Stabilizer

Refers to chlorine stabilizer, the final part of outdoor pool water balance. This is a chemical that prevents the ultra-violet rays (UV) of sunlight from prematurely breaking down your sanitizer level so that it can do its job sanitizing the pool. Stabilizer need only be added once a season and typically will reduce sanitizer consumption by up to 50 %. For optimum performance, the stabilizer level should not exceed 100 ppm. If applying Stabilizer 100, do not backwash for at least 24 hours.

Testing & Sanitizers

Pool and spa water has chemical characteristics that must be measured regularly. For an in-depth computerized analysis, we encourage you to bring in a water sample and we’ll run a complete test with Bioguard’s ALEX software program. We strongly recommend doing this once a month and it’s totally free.

Pool and spa owners have a responsibility to check two of these characteristics on a regular basis.

1. pH
2. Sanitizer (Chlorine or Bromine)

By testing these two factors on a regular basis, a pool or spa owner can understand how bather load, weather conditions and chemical applications affect the water. For example: The warmer the water, the greater the use of chlorine. The greater the bathing load, the greater the use of chlorine. Testing is important because water maintained in the proper ranges will be:

• Protected from uncontrolled bacteria growth
• Clear, sparkling, inviting
• Comfortable to the eyes and skin of swimmers
• Less aggressive to pool surfaces and equipment
• Protected from growth of algae

Now that you water is properly balanced, it is time to sanitize it with chlorine. There are many types of chlorine, but the most economical and convenient choice is to use a chlorine generator which generates chlorine from salt. You should always maintain a level of 1.0-5.0ppm of available chlorine. These levels allow for continuous killing of bacteria, algae and other micro-organisms that try to inhabit your pool.

Shock Treatments

Various contaminants such as swimmer waste, lotions and oils can resist normal chlorination and start to build up in the pool water. This usually occurs during periods of heavy bathing when your filter is already working overtime. A weekly shock treatment per label direction is recommended. This will oxidize or burn-up these contaminants. It is best to apply Bioguard’s Burnout Extreme shock in the evening so that it can work overnight and be down to normal levels the next day. Be sure to continue to run your pump and filter during this period of time.