The most dramatic thing I learned while researching frugal living for my book was that a lot of things I “knew” about saving money just aren’t true. When I realized that, I made it my mission to test anything I reasonably could before putting it in the book. The people who write articles for the internet aren’t always given the time or the budget to fully investigate the ideas they write about. Even authors of full-scale books sometimes can’t test an idea, but it sounds reasonable and it’s been in other books, so it gets included.
“Showers use less water than baths.” Everybody “knows” that. But the truth is that it is only true sometimes. I tested this idea by taking a shower with the plug in the bathtub drain. I took an ordinary no-frills shower in a shower that had a full-flow shower head. The tub filled to about where I would have filled it for a bath, 32 gallons. If I had stood a while letting the hot water run over my back, or if I had left the water running while shaving my legs, it would have used a lot more water than a bath, even more than the tub would hold. When I took the same no-frills shower in the bath that has a low-flow shower head it used a little over half as much water. So with the low-flow I could have stood under the soothing hot water for a few extra minutes and used as much water as a bath takes.
Someone who’s serious about reducing water use might take a “military shower”, in which you turn on the water just long enough to get wet, leave it off while you soap and shampoo, and then turn it on again just long enough to rinse off. That type of shower really will use less water than a bath.
My compromise is to use a flow controller valve installed above the full-flow shower head. The valve cost about $10 at a hardware store. It lets me turn the volume of water down or off, without bending over to the faucets and getting soap in my eyes. I have the luxurious feeling of a full flow shower when the water is on, and when I don’t need the water it’s easy to turn it off or turn it to a low or very low flow.