How do you keep the PH down? Do you keep adding acid? It seems so corrosive. I've added a gallon over the course of a week but my PH is still too high. How much can you add at once? It's 30,000 gallons and the acid is 31% concentrate. Also, my chlorine level is high and the pool smells bleachy and from what I've read that means I should be adding more liquid chlorine or shocking...do you think that's right?