My wife and I recently bought a house and the pool was not taken care of for a long time. The water was almost black when we took the cover off. Since then, by adding shock and other chemicals, it got to a medium shade of green and cloudy...we can only see about a 1/4 of the way down if that. We had the water tested, added alkalinity to raise that as well as more shock and algaecide, but the water does not get any better. Our Free Chlorine is extremly low, but I was told not to worry about that this time of year. Should I add some liquid chlorine to raise that up to help the color and cloudiness? Aside from that, what else should I do to get this water cleared up before I have to close it? Is flock the answer?