I brush my teeth in the shower. Of course, I only brush once a day but nevermind that. I just don’t see the need to run a separate lot of water to get my teeth clean, when I’m already spending at least twenty minutes in the shower anyway.
I brush in the shower as well – I just couldn’t resist the urge to stick it to the casinos. They waste water like nobodys business. 
When I was a kid, I turned it off. Now I usually brush in the shower, but when I brush over the sink (or outside of home), I leave the water on because I hate toothpaste residue sticking to the sink and with the water on it washes right away. I figure, I’m paying for it, so I can do what I like.
I leave it running but only at a trickle. I do this because brushing my teeth makes me gag and throw up, rinsing with warm to hot water seems to lessen this problem. If I waited and ran the waterto heat after I was done, it would make me be sick and I would have to brush my teeth again. I take medications after I brush. I sometimes have to lay down for a few minutes after brushing my teeth. I turn the water off then. 
I leave it running but, then again, I’m on a well and septic.
So it goes down my drain, through the septic, into the drainfield, seeps down into the water table and gets pumped back up at some later point. Really, it’s just visiting me for a few moments.
My stars, that’s what I came in here to post. I never watched Da’ Street much growing up, but I do remember this one clip. Always has stuck with me. Of course I came to the other conclusion at the time, because my grandma took me fishing a lot. Low water levels means easier to catch fish…
But now, I think I turn the water off. I can’t honestly remember, though.
It is particularly wasteful because it provides you no utility whatsoever - the very definition of wasteful. Whether it’s a wastefulness that has an overall impact is another question; if the figures elsewhere in this thread are correct and an entire 1% of US water usage is wasted this way, I’d say that was an absolutely appalling waste.
A water shortage in the UK? What the heck? Did it stop raining?
Someone in my dorm pointed out that you may as well turn the tap off while you brush, and I’ve left it off since then. I could never bring myself to try her recommended “military” showers (turn the water on, get in, then turn it off while soaping yourself up, and only turn it on again to wash off the soap). That was just too much.
Not completely , but there has been less than average rainfall in the south of England for the last couple of years.
See this story
and this
I do it. I have no idea why. I suppose to allow the water to warm up a little but from the time I wet the brush to when I rinse out.
I don’t wet my toothbrush before I brush so I don’t turn on the water until the first time I spit. By then I’m two-thirds of the way finished.
I would be one of the group that leaves it running so the water is warm for shaving. Our water takes ages to make the cold to warm transition, so it would be MORE wasteful to turn it off while I brush just to have to let it run again to heat so I can shave.
I’m another one that brushes in the shower, I always thought I was the only one!
It seems so much easier to me, it doesn’t matter if you dribble toothpaste on yourself, you are in the shower fer Og’s sake. Also, it makes rinsing a quick and easy afair, just tilt your head back and open your mouth.
I had a girlfriend who tried to cure me of this once. It worked for awhile, but I reverted to my old habits after we broke up.
I tend to hang my head over the sink and let the foam dribble out my mouth while I’m brushing, and I guess it’s nice to have running water to rinse it down the drain before it can congeal. And it’s much more fun to stare at swirling water than globs of congealing foam.
Plus water’s plentiful and cheap here.
None of this adds up to a good reason to leave the water running, but habits are habits.
I leave it running - not particularly quickly though. Like saoirse I rinse frequently, and turning it off is a pain. Really it’s just habit, though.
I leave it running when washing up too - again, only slowly. I do this because unless I’m washing loads of pots, I use less water that way (I’ve tested this), and each piece of crockery gets nice clean water.
Don’t be so quick to assume that after going down the drain it’s “back into the system”. It depends upon where your system obtains the drinking water from in the first place. If the water comes from a nearby river, ok, it is “back in the system”. Or if you live in an area where underground aquifers recharge, ok. However, for example, some of our aquifers here are water bodies “trapped” underground and do not recharge. Therefore, if I run well water unnecessarily I am wasting it.
Also, in those which do recharge, it’s good to try to keep usage below their recharge rate:
I leave it running because I can. We have so much water in my community that we pump it straight out of the ground to feed 5 river fountains capable of 50 to 100 ft streams. (they run on a timer unless there is a special event going on).
Actually, I often shut it off because I walk around the house when brushing so it depends on what I’m doing.
Maybe I just have a wierd ass way of brushing my teeth but I don’t see even a reason for leaving water on when brushing. Heres how I do it:
- Fill my plastic cup with water
- swish the toothbrush around to get it wet
- take a mouthful of water, swish, and spit to get mouth wet
- apply toothpaste to brush
- brush teeth
- rinse out mouth once
- brush teeth again
- rinse out mouth twice to get it clean.
- refill cup 1/2 way with water
- swish toothbrush around in cup
In total, I use about 1 1/2 cups of water and I don’t see any reason at all why having the water run in between would be avantageous in any way. Am I just a tooth brushing freak?
As a kid I ran water when I faked toothbrushing.
But nobody was fooled.
You don’t start the water until after you’re done brushing. Why would you?