Silver prevents bacteria and algae from building up in their filters so that they can do their job to rid drinking water of bacteria, chlorine, trihalomethanes, lead, particulates and odor.

There is no problem in using silver or gold in purifying water. The Prophet has only prohibited using silver and gold utensils for drinking. He is reported as saying, “Verily, the person who eats or drinks in utensils made of gold and silver.” (Al-Bukhari)