Use and Care Manual
Coleman Roto Mold Spa (online sales)
LTR50001136, Rev. A
Clear Water Plan
18
Testing and Adjusting Spa Water
You have two types of testing methods to choose from:
The reagent test kit •  is a method which provides a high level of accuracy. It is available in either liquid 
or tablet form.
Test strips •  are a convenient testing method commonly used by spa owners.
Balancing the pH
The  pH  level  is  the  measure  of  the  balance  between 
acidity and alkalinity. 
If the pH is too low, it can cause corrosion of metal x-
tures and the heating element. Low pH can be corrected 
by adding a pH decreaser.
If the pH is too high, it can cause scaling by allowing met-
als or minerals to form deposits and stain spa surfaces. 
High pH can be corrected by adding a pH increaser
8.2
8.0
7.8
7.6
7.4
7.2
7.0
6.8
6.6
Too alkaline,
causes scaling
Ideal balance
Too acidic,
causes corrosion
Need to lower the pH level
Need to raise the pH level
Balancing the Total Alkalinity
Total  alkalinity  (TA)  is  the  measure  of  the    total 
levels of carbonates, bicarbonates, hydroxides, and 
other alkaline substances in the water. TA can be 
considered a “pH buffer”. It is the measure of the 
ability of the water to resist changes in pH level.
The recommended total alkalinity is 80 - 120 
ppm. 
If the TA is too low, the pH level will uctuate wide-
ly from  high to  low. Low  TA  can  be corrected  by 
adding an alkalinity increaser
If the TA is too high, the pH level will tend to be too 
high and may be difcult to bring down. High TA 
can be corrected by adding an alkalinity decreaser.
When the TA is balanced, it normally remains sta-
ble, although adding water with high or low alkalin-
ity will raise or lower the TA level.
Balancing the Calcium Hardness
Calcium  hardness  (CH)  is  a  measure  of  the  total 
amount of dissolved calcium in the water. Calcium 
helps control the corrosive nature of the spa’s wa-
ter and is why soft water is not recommended. The 
low calcium content of soft water is very corrosive 
to the equipment and can cause staining of the spa 
shell.
The  recommended  calcium  hardness  is  150 
- 200 ppm.
If  the  CH  is  too  low,  add  a  calcium  hardness  in-
creaser.
If the CH is too high, dilute the spa water with soft 
water.
When the CH is balanced, it normally remains sta-
ble, although adding soft water or very hard water 
will raise or lower the CH level.
Testing For: Ideal Range (ppm) Chemicals To Use:
Minimum Maximum To Raise To Lower
Total Alkalinity 80 120 pH-Alkalinity Up pH-Alkaliity Down
Calcium Hardness 150 200 Liquid Hardness Increaser Stain and Scale Defense
pH 7.4 7.6 pH-Alkalinity Up pH-Alkaliity Down










