And nowadays a large part of the lakes, rivers and even some nearland sea areas have already been polluted. The water is no longer safe to drink as causually as in the past time. So a water purifier is necessary for one household .The necessity is as the same importance as some other household appliances, such as a refrigerator, a TV set. If one family has a water purifier, then they can use the useful equipment to filter or purifier the water which is going to be drinked. Sometimes when the tap water is not so clear even though there is already some bleaching power thown into the water, then all the water that is to be used either for drinking or for other uses must be filtered by the water purifier.