Nava 652029353 25lb Alkalinity Booster. Alkalinity Booster (sodium bicarbonate) is used to raise the alkalinity which has a recommended range of 100-150ppm in plaster and marsite pools and a recommended range of 125-175ppm in fiberglass and vinyl pools. Alkalinity is important in the prevention of corrosive water conditions and to buffer the water to avoid rapid fluctuations in pH. In addition to plaster etching and accelerated corrosion; low alkalinity can cause the water to take on a green tint. Maintaining the proper alkalinity range is also important to swimmer comfort.