When filters reach their saturation point, they can introduce into the water the very contaminants that would otherwise be trapped and filtered. Put a little food coloring in your toilet tank. If, without flushing, the color begins to appear in the bowl, you have a leak that should be repaired immediately. Check faucets and pipes for leaks. Even the smallest drip from a worn washer can waste 20 or more gallons a day.
Larger leaks can waste hundreds.
Stop using toilet as an ashtray or wastebasket. Every time you flush a cigarette butt, facial tissue or other small bit of trash, you waste five to seven gallons of water. Take shorter showers. Every minute of the shower uses five to ten gallons of water. Installation of water-saving shower heads will help.