As tenax says, keeping the cover off is the best way to lower your chlorine. Sunlight (UV) will breakdown the chlorine faster than most anything else so keeping the cover off during the day is more important than keeping it off at night (in case you wanted to retain heat). If your pool is in full sun most of the day, you could lower the FC by about half of its amount each day. Of course, this time of year there is less sunlight.

Richard