IWA Publishing

Skip to Main Content

Table 1

Description of two heated indoor swimming pools under investigation

Parameter	Unit	Pool 1	Pool 2
Chlorinator		Automatic dosing with ORP control	Automatic dosing with digital timer control
Stock chlorine		Calcium hypochlorite tablets with 65% active ingredient	12.5% sodium hypochlorite solution
Pool size	m³	901	492
Average daily bathers^a		34	179
Total water change		Approx. 1 year	Approx. 1 year
Make-up water %	day⁻¹	1.9%	1.7%
Water temperature^a	°C	28.6	29.8
Conductivity^a	μS/cm	1128	7102
pH^a		7.56	7.30
Alkalinity^a	mg/L as CaCO₃	70	36
Free chlorine^a	mg/L as Cl₂	2.43	1.35
Combined chlorine^a	mg/L as Cl₂	0.57	1.19
Chloride^a	mg/L	119	789
Nitrate^a	mg/L	3.8	4.2

Parameter	Unit	Pool 1	Pool 2
Chlorinator		Automatic dosing with ORP control	Automatic dosing with digital timer control
Stock chlorine		Calcium hypochlorite tablets with 65% active ingredient	12.5% sodium hypochlorite solution
Pool size	m³	901	492
Average daily bathers^a		34	179
Total water change		Approx. 1 year	Approx. 1 year
Make-up water %	day⁻¹	1.9%	1.7%
Water temperature^a	°C	28.6	29.8
Conductivity^a	μS/cm	1128	7102
pH^a		7.56	7.30
Alkalinity^a	mg/L as CaCO₃	70	36
Free chlorine^a	mg/L as Cl₂	2.43	1.35
Combined chlorine^a	mg/L as Cl₂	0.57	1.19
Chloride^a	mg/L	119	789
Nitrate^a	mg/L	3.8	4.2

^aData presented are averages of samples analyzed during the 8-week investigation period.