We recently opened our pool and are having a problem with combined chlorine and ammonia. I have a 33,000 gal vinyl in ground pool (fc 0.5, cc 5, pH 7.2, TA 140, CH 160, CYA 0). I can't get the FC level to budge above 0.5-1.0 and the combined chlorine is reading 5+. Based on discussions on this...