I don't know if this makes a difference but the building is "see through" and has doors that open at the side. We have had little sun here in North Idaho so have had the building closed. It is suppose to get up to hundred this week so I will open up the building with hopes the sun will burn up some of the chlorine. For now I will not empty and see what happens. Maybe this is why I have had problems as it has been cold and wet this year more than usual and the building has been closed? Who knows. I scratch my head daily wondering what went wrong. There has also been work done on the well system over the past year in the neighborhood and anything can be added for all I know. We have a water filter on the system to help get rid of contaminates. It has helped some with the TA.