352
PO
S AVE THESE INSTRUCTIONS
(352PO) SPA ENGLISH 7.5” X 10.3” PANTONE 295U 12/16/2021
English
Page 22
SPA WATER CHEMISTRY AND BALANCE (continued)
Lowering pH Using Sodium Bisulfate
Calcium Hardness Adjustment
Use the included test strips to check the water hardness level and adjust it following below chart.
Lowering Calcium Hardness
If your household water supply is treated with a softener, mix the spa hard water with the soft water
according to the water volume ratio chart to lower the calcium hardness:
Initial level
1000 ppm
500 ppm
350 ppm
250 ppm
Desired level:
100 ppm
Water Volume Ratio
(Vhard water:Vsoft water)
1:9
1:4
2:5
2:3
Lowering Calcium Hardness Using Soft Water
Raising pH
Raising pH Using Sodium Bicarbonate
WARNING
Muriatic acid is a caustic chemical and liquid solution of sodium bisulfate (NaHSO
4
)
is highly acidic. Handle all chemicals with care and wear extra personnel protective
equipment including goggle and gloves. It is very important not to splash acid onto
your skin or clothing, or into your eyes.
Lowering pH
Lowering pH Using Muriatic Acid
Volume
210 gal (795 L)
290 gal (1098 L)
Total Alkalinity
120 ppm
80 ppm
120 ppm
80 ppm
From→To
8.4→7.2
0.028 qt
0.018 qt
0.038 qt
0.025 qt
26 mL
18 mL
36 mL
24 mL
7.8→7.2
0.019 qt
0.013 qt
0.026 qt
0.017 qt
18 mL
12 mL
22 mL
16 mL
Volume
210 gal (795 L)
290 gal (1098 L)
Total Alkalinity
120 ppm
80 ppm
120 ppm
80 ppm
From→To
8.4→7.2
0.071 Lb
0.047 Lb
0.095 Lb
0.063 Lb
32 g
21 g
43 g
29 g
7.8→7.2
0.047 Lb
0.032 Lb
0.064 Lb
0.043 Lb
21 g
14 g
29 g
20 g
Volume
210 gal (795 L)
290 gal (1098 L)
Total Alkalinity
120 ppm
80 ppm
120 ppm
80 ppm
From→To
6.8→7.2
0.541 Lb
0.361 Lb
0.737 Lb
0.491 Lb
243 g
163 g
335 g
224 g
Raising Calcium Hardness
If the calcium hardness level in the spa water is lower than 100 ppm, add calcium chloride into the spa
water.
Volume
210 gal (795 L)
290 gal (1098 L)
m (CaCl
2
)
0.197 Lb
89 g
0.269 Lb
122 g
