The recommended a slightly higher pH range for your spa water, 7.2-7.6. 
The pH level is a measure of acidity and alkalinity. Values above 7 are alkaline; those below 7 are acidic. Maintaining the proper pH level is extremely important for: 

• Optimizing the effectiveness of the sanitizer.
• Maintaining water that is comfortable for the user.
• Preventing equipment deterioration.

If the spa water's pH level is too low, the following may result: 

• The sanitizer will dissipate rapidly.
• The water may become irritating to spa users.
• The spa's equipment may corrode.

If the pH is too low, it can be increased by adding Arctic Pure™ Adjust Up to the spa water. 
If the pH level is too high, the following may result:

• The sanitizer is less effective.
• Scale will form on the spa shell surface and the equipment.
• The water may become cloudy.

If the pH is too high, it can be decreased by adding Arctic Pure™ Adjust Down to the spa water. 
It is important to check the pH on a regular basis. The pH will be affected by the bather load, the addition of new water, the addition of various chemicals, and the type of sanitizer used.