Public water system must produce pure water strictly meet standards to be sure it is safe for drinking. However, that does not mean it is void of all contaminants. Tap water may contain pollutants effect on the taste, color and smell of water. Water filter systems, like Reverse Osmosis filter, will remove pollutants from the water. These systems, also known as faucet water filters, in this study the activity of water filter (kifllow) which widely used in Iraqi houses was tested through compared the tap water quality before and after entrance to this filter this drinking water systems filter contain six different stages. Each stage or filter gives results different from the others.