pH Plus - increases pH levels in Spa water
The pH scale has a range of 0 - 14. 0 being very acidic, 7 being neutral and 14 being very Alkali.
It is essential to maintain spa water within the 7.2 - 7.6 range which, being slightly alkaline will protect equipment from corrosion and provide the optimum conditions for bather comfort and sanitiser efficiency.
If spa water pH falls below 7.2 use pH Plus as directed.
If spa water pH exceeds 7.6 use pH Minus as directed | 
