I just received my Nautilus and was reading the directions and it notes that the maximum chlorine level for operation with the Nautilus is 4 ppm. This is a bummer because I just put chlorine in this afternoon and it's probably about 6 ppm right now, so that means I can't use it until tomorrow. Does anyone know if it's okay to use if the level is a little over 4 ppm, like 6 or 5? Why is there a max chlorine level anyway? TIA!