I'm sure this has been addressed here before and I apologize for asking again. We came back from a week's vacation to find our salt water pool a dark greenish-brown color. It has never been like this, even in the spring. There was a ball stuck in the skimmer so the water was not properly filtered while we were gone. We had the water tested and were told that our chlorine was at 0, so we upped the generator from 3 to 5. We added a product called "green to clean" and 2 bags of shock. What else can we do?