how much does doing water changes effect your water bill. and im asking from experiences. i live in visalia california and i currently have a fifty gallon half full and i honestly don't do a lot of water changes, for some reason my water level never really change and the last water change i did was three months ago. well anyways back to the question at hand, my girlfriends dad whom we live with says that the water bill is now 500 dollars and i highly disbelief its from my one fifty gallon with twenty five gallons of water in it. anyone care to enlighten me?