Proper Swimming Pool Chemical Levels

Proper Servicing and maintenance is crucial to minimizing long term expenses on swimming pools, spas, and water features.  Chemical balance is probably the single most important factor in maintaining your swimming pool, spa, or water feature. If a swimming pool is not maintained within proper chemical guidelines it will cost the owner thousands of dollars in excessive repair bills. The National Swimming Pool Institute has created a standard which is widely accepted as the guideline for pool water balance. When maintaining pools, spa’s, and water features in accordance with NSPI standards you will provide a safe and sanitary environment for everyone using the pool. Below we have a chart that indicates the ranges your swimming pool, spa, or water feature chemicals should be kept in.

Chemical Ideal Level  Minimum Level
Free Chlorine 2-4ppm 1ppm
Combined Chlorine 0 0
Alkalinity 80-120ppm 60ppm
Calcium Hardness 200-400ppm 150ppm
PH 7.4-7.6 7.8
Cyranuric Acid (Stabilizer) 50ppm


ORP Reading if Installed None

650 Millivolt

Total Dissolved Solids NA

1500ppm over beginning water reading

The chart above shows guidelines that are generally accepted as safe.  However, there are instances when these values may be adjusted.  For example salt water chlorinators generally require that cyanuric acid (stabilizer) levels be kept at 70ppm.  Also, if you have a commercial pool with an ORP feeding system installed you may be required to keep the minimum ORP reading at a higher level to maintain the proper ppm chlorine requirement for sanitation purposes.