I just treated my hot tub with Ahh-Some before draining and refilling. I shocked with 2.5 T. diclor per directions with Nature2 for my 400 G spa and the chlorine level is still above 10 PPM FC after 14 hours. The cover is off. I'm getting impatient and curious about any negatives with using Sodium Sulfite or sodium thiosulphate to bring down the chlorine?