The Fibredyne 10" Bacteriostatic  1µ  cartridges are Modified Molded Block powdered carbon  cartridges and are  Silver impregnated for bacteriostatic properties. Silver prevents bacteria and algae from building up in the filters so that they can do their job to rid drinking water of bacteria, chlorine, trihalomethanes, particulates and odour.  They are Ideal for  low pressure and tank water.