My blue devil is an oto kit , ph 7.2-7.4 , chlorine 5 or higher because that as high my test kit goes , ta 120 , cya 0 , calcium 160 , free chlorine unknow , list of chemicals I have are 4 - 1 lb of shock ( calcium hypochlorite ) 67% , 1 - bucket of 3" tablets ( trichloroethane- s- triazine , 5 lbs Bulk Ascorbic Acid Powder that I was going to use to help remove tha stain. Thanks for your help