Proper chemical treatment and balance is very important in your swimming pool.  A wide range of problems can occur if the water is not properly balanced.  These problems can include, but are not limited to, scaling, algae growth, cloudy water, corrosion of the pool surface and/or your equipment.

To prevent these problems from arising, you should test your water chemistry regularly. Check it a minimum of once a week during the swim season and at least every two weeks during the off season (unless you winterize your pool).  Following are general chemical levels that should be maintained in your pool or spa.

ppm = parts per million

Baquacil (Baquanide) is a sanitizer that is also called PHMB. It is known as “non-chlorine” sanitizer.  PHMB is free of chlorine odors and irritations.  You must add an oxidizer to the Baquacil in order for it to be effective (see mfg. instructions).  The ideal range is 30 – 50 ppm striving to be closer to the 50 ppm mark.  You may NOT introduce chlorine or bromine if you have a baquanide pool, if added these products can cause the formation of a gummy deposit on the surfaces and pipes.  The product is stable and will stay in the water it needs to be added only in top off doses every week or two.

pH is the term used to measure the degree of acid or base in the water.  It is the most important chemical factor in swimming pool water. pH can be effected and changed by the use of a sanitizer in the pool.   Since the sanitizer is the most frequently added chemical to the pool, it has a powerful impact on the pH.  When pH is low (7.2 or lower) damage can occur on the plaster such as etching.  It can also cause damage to the metals in heat exchangers. High pH, (above 7.8) will increase the tendency for scale and cloudy water. pH is lowered by adding muriatic acid or sodium bisulfate. pH is raised by adding sodium carbonate.

Total Alkalinity is a measure of how much of the alkaline substances there are in the water. The main purpose of Alkalinity is to help manage the pH.  When the alkalinity is below 80 ppm, the water can become aggressive and the pH can easily swing too far  upward or too far downward. If the value is above 120 ppm the water can become cloudy and form scale and the pH will drift upward.   To lower alkalinity you can use small amounts of acid (liquid or dry). This needs to be done slowly.  If you need to raise alkalinity, sodium bicarbonate can be added to the water.   When the pH is low and alkalinity is high, lower the alkalinity first to normal levels) then raise the pH.  When the pH is high and alkalinity is low, raise the alkalinity first then lower the pH. Doing this in proper order will save you money on chemicals.

Calcium Hardness is the sum of all the calcium dissolved in the water.  Calcium is important since high calcium levels are more unstable if the pH or total alkalinities are above normal levels.  These imbalances can result in cloudy water and/or scale.  If the calcium is too low, calcium chloride (hardness increaser) can be added to the water.  If the calcium is too high the only way to combat this is by diluting the water with water that has lower calcium levels.  An alternative to diluting the water is to minimize the effects of the high calcium with a sequestering agent.  The sequestering agent will bond chemically with the calcium and other minerals in the water and make them more soluble.  They are still in the water but are less likely to cloud the water or form scale.

Total Dissolved Solids (TDS) are the least worrisome factors in pool chemistry.  TDS is the sum of all materials dissolved in the pool.  There is no low limit for TDS, if TDS gets above 1500 ppm you may want to drain some of the water out of the pool and re-fill. (* Caution needs to be applied when draining a pool as damage can occur.  It is recommended that you consult the advice of a pool professional.  When draining a fiberglass pool or a pool with vinyl liner damage can occur with even a partial drain.) High TDS may lead to cloudy or hazy water, difficulty in maintaining water balance, reduction of sanitizer activity and foaming. 

**Always refer to the manufacturer’s recommendations for chemical doses when adding chemicals to your pool or spa water.  You should also know how to figure the gallons of water your pool holds: See "How to Calculate Pool Size"

**Treat all chemicals with respect and care. When mixing chemicals in a bucket always add chemicals to water NOT water to chemicals