... the cost, but also have high effect of de-nitrogen, de-ammonia, de-phosphor as to 99%, it is ideal replacement for quartz sand ... rate of NaOH%1.50Void space%55SoluteNO dangerous rare element to humanBreaking and wearing rate%1.62In gear filtering speed (m ... )20-40Acid resistanceUses 98%, 40%, 20%, 5% sulfuric acid solution to soak for 30 days, the loss in weight is smaller ...