(1) Water chemistry, temperature, and clarity measurements must fall within the parameters set forth in Table 6:

 

Table 6.

 

Parameter	Acceptable	Ideal
Chlorine	2-8ppm	3-5ppm
Combined chlorine	0 to 0.5ppm	0.0
Bromine	2-10ppm	2-8ppm
Total Alkalinity	60-220ppm (varies by chemical type and pool surface)	80-100ppm for Cal Hypo, lithium hypo, and sodium hypochlorite; 100-120ppm for Sodium dichlor, trichlor, chlorine gas and bromine compounds
Oxygen Reduction Potential (ORP or HRR, which stands for High Resolution Reduction)	650 minimum millivolts (mV)	650-750 minimum millivolts (mV)
pH	7.2-7.8	7.4-7.6
Cyanuric Acid (allowed only in outdoor pools)	0-100ppm	10-50ppm
Calcium Hardness	Pools 150-1,000ppm	Pools 200-400ppm; Spas 150-250ppm
Temperature	Pools may not exceed 100º F Spas may not exceed 104ºF Flow through hot springs may not exceed 106ºF
Clarity	NTUs must be in the range of 0.0-1.0. See ARM 37.115.1315(1)	0 NTU

 

 

(2) If total alkalinity is too low, it will result in pH bounce and a tendency to cause corrosion. If total alkalinity is too high, it will result in cloudy water increased scaling potential and a tendency for pH to be too high.