Install a low-flow toilet or tank water saving device and save as much as five gallons of water a day. Install a low-flow showerhead and save as much as 86 gallons of water a day. Install a sink aerator and save eight gallons of water a day. Turn off the faucet while you brush your teeth and save 4 to 10 gallons of water a day. Fix your leaky faucet and save as much as 7 gallons of water a day. Only run your washing machine and dishwasher when they are full. You can save as much as 15 gallons per load for the dishwasher and 55 gallons per load for the washing machine.