How much soda ash per gallon do you add in a swimming pool for cloudy water?

You don't really add soda ash for cloudy water; in fact depending on the situation it can cause cloudy water. Soda ash increases pH. You have to use large quantities of liquid chlorine 12.5% and 24/7 filtration. Normal run time for filter would be in the neighborhood of 12 hrs depending on size of pool.