Wikipedia:Reference desk/Archives/Science/2018 November 21

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November 21[edit]

Should I drain my water glass or leave it overnight?[edit]

I was wondering it is safe to leave glasses of water out overnight, or should I drain them/turn them upside down. I remember watching a USA training film for the Pacific Theatre which said to let utensils and service air dry instead of towel drying to prevent germs, but I wonder if sitting water can breed bacteria. Everything I find on the internet is just about "flatness", flavour, pH, carbon dioxide etc etc but not about bacteria. 03:25, 21 November 2018 (UTC) — Preceding unsigned comment added by 68.229.214.195 (talk) My current water supply is chlorinated, but I've been at locations where it wasn't.68.229.214.195 (talk) 03:27, 21 November 2018 (UTC)[reply]

The water wont breed germs but all the Birds and Insects that like to take a sip may. Especially Birds love the smallest puddles of water for a morning wash. Insects probably too. Towels are only usefull to polish off fat marks from fingers and lips which wont go off from washing with water.
Anyway germs are everywhere but in technical cleanrooms which are constantly filtered and desinfected, so best get used to the idea that most "cleaning" is cosmetical unless you use heavy chemicals. --Kharon (talk) 05:39, 21 November 2018 (UTC)[reply]
Would you really want to drink water that's been sitting stagnant overnight? Is your refrigerator not working? ←Baseball Bugs What's up, Doc? carrots→ 06:06, 21 November 2018 (UTC)[reply]
The OP might, like me, like to have a glass of water (or other cool beverage) on a bedside table to drink if wakened during the night, rather than having to get up and go downstairs to the kitchen. In my experience, clean water (etc.) in a clean glass indoors does not achieve a state of stagnancy in a mere few hours overnight.
My own practice, OP, is to cover the top of the glass with a plastic lid to keep out any gnats, dust, etc. I find the lid from a Pringles tube admirably suited for the purpose, but various other recycled plastic pot lids would be equally suitable. {The poster formerly known as 87.81,230,.195} 90.200.131.235 (talk) 07:12, 21 November 2018 (UTC)[reply]
A friend told me that he switched to keeping bottled water by his bed after noticing the cat was shoulder deep in his water glass looking for a fish he could scoop out. He said that you can refill the water bottle from the tap for three or four days, but after that is starts to smell funny. --Guy Macon (talk) 07:20, 21 November 2018 (UTC)[reply]
Something unbreakable and with a lid on it is definitely a good idea. A better choice than bottled water could be one of those plastic mugs with a closeable top. With two of them, one could dry upside down in the dish drainer (after washing it) while the other's being used that night. ←Baseball Bugs What's up, Doc? carrots→ 13:21, 21 November 2018 (UTC)[reply]
I've found that a lid that forms a tight seal can cause the humidity in the glass to rise to the point that it starts to smell mildewy. I cover my glass with a tissue instead. --Ahecht (TALK
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Thanks for the help everybody.68.229.214.195 (talk) 16:13, 21 November 2018 (UTC)[reply]
Just a question: does putting a pure silver coin in the water help? That's what I read that they used to do on ships, to stop the water from spoiling. Will it prevent the mildew developing? Will the anti-bacterial action of the silver be sufficient to stop the buildup of bacteria in the water? And is there a danger of ingesting too much silver, due to the leeching into the water? Eliyohub (talk) 11:05, 24 November 2018 (UTC)[reply]