A 30 minute shower uses more water than a bath.

If you don't believe me, try plugging the drain on just a 5 minute shower to see how much it fills up, then extrapolate...

(The shower crosses into more water generally somewhere between 10 and 20 minutes depending on the shower flow and desired bath depth...)

Every shower head is a minor restriction on flow compared to the bath faucet. It may or not be negligible. But a bath drawn for the same faucet runtime will use more water than the same runtime for a shower every time. The crossover in cost happens when the shower uses more water than the bath. That should happen very shortly after the time it takes to fill a bath. At one house, our bath took 40 minutes to fill, another 15-20, and another took under 10.

Only on HN someone wonders what's the cost of a shower, another person actually attempts to calculate that, and then we get into a discussion whether 30 minute showers are a good thing or not. IMO 30 minutes is a bit excessive but I do enjoy longer showers myself ;)

In grad school, many years ago, I would plug the drain and let the tub fill while I showered. I would pull the plug and let the tub drain once the water had cooled. This way my bathroom would warm up a bit. I suppose this might have saved a few cents.

These days you can get passive ‘waste water heat recovery’ systems that sit beneath a bath or shower tray - warming your inbound cold water with your outflow, so you use less new hot water (or have to heat it less).

I'd be curious to know how these systems manage with dissolved soap, partially dissolved skin cells, hair, etc.

> I personally don't understand the people who wouldn't want to take a 30 minute shower.

Are you aware that clean water is a finite resource that we're almost certain to run out of? [1] does that not bother you all?

Even mighty British Columbia with all the rivers, lakes, mountains and snowfall is under drought conditions, right now in winter!

https://www.theworldcounts.com/challenges/planet-earth/state...

> > I personally don't understand the people who wouldn't want to take a 30 minute shower.

> Are you aware that clean water is a finite resource that we're almost certain to run out of? [1] does that not bother you all? https://www.theworldcounts.com/challenges/planet-earth/state...

I think a 30 minute shower contributes to a global water shortage in the same way that plastic straws contribute.

The link you’ve provided says 90% of water usage is on the generation of electricity, food, and products.

I think the GP should continue to take 30 minute showers, because even if they stop, even if every person stops, it’ll have a negligible effect on water usage.

Much like plastic straws.

What do you mean it's a finite resource, I take a shower with some water, it gets dumped, cleaned then I can use it again. Does me taking a longer shower just disintegrate the water?

GP did not consider septic tanks either apparently

With unlimited energy, there's pretty much infinite water in oceans to desalinate. Energy and its clean production and storage is the only thing to worry about.

> Are you aware that clean water is a finite resource

It kinda is, when you're drawing it from a spring that will lead to the ocean one way or the other.

It's terrible for your skin.

Agreed, although I don't think this was a problem for me until I was in my 30s or so.