Alkalinity Increaser 2nd June 2014 View basket “PH Reducer / Minus 1.5kg” has been added to your basket. £7.50 Alkalinity Increaser will lift the total alkalinity helping to prevent wide fluctuation of pH, which can cause damage to spas and hot tub equipment and finishes. Quantity Add to basket Category: Chemicals Related products Stabilised Chlorine Tablets 5kg £45.00 Add to basket Pure Spa Salt 5 Kg £22.00 Add to basket