We are a professional zeolite manufacturer, our production ability is 150,000 tons per year,it is the NO.2 in China. Our 4A Zeolite is the substitute of STPP. Please ref our main specification as below, 1. excellent Ca Ion Exchanging Rate >320 mg caco3/g, strong soften ability 2. High and stable Whiteness >97 , it make your detergent powder whiter 3. PH1%, 25PH Value