You know that book Everyone Poops? They ought to make another one to go along with it: Everyone Flushes. Because everyone does, and a looooooot of water gets wasted along the way. While today’s toilets use less water than the bowls of old, that’s no help to many apartment-dwellers and others who are stuck with aged commodes. Today a Grist.org reader asks how to save water when pulling the lever, and advice columnist Umbra Fisk gushes forth solutions.