Adding 2 oz. of sodium bicarbonate (baking soda) per 1000 gallons of water will raise the alkalinity 10 parts per million. Despite raising the alkalinity to the desired level in my vinyl-sided pool the pH was not adversely affected. Increasing the pH of the water without affecting the alkalinity is very easy, but there is a trick. With the pump motor on and water circulating, add the sodium bicarb. in the deep end of the pool and work your way around the perimeter. This will raise the pH with minimal effect on the alkalinity.