# black humidifier water?

**URL:** <https://boards.straightdope.com/t/black-humidifier-water/479928>\
**Category:** Factual Questions\
**Created:** [January 5, 2009, 9:56am UTC](https://boards.straightdope.com/t/black-humidifier-water/479928 "2009-01-05T09:56:33Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jcs1701](https://avatars.discourse-cdn.com/v4/letter/j/71e660/32.png) [@jcs1701](https://boards.straightdope.com/u/jcs1701)\
**Post date:** [January 5, 2009, 9:56am UTC](https://boards.straightdope.com/t/black-humidifier-water/479928/1 "2009-01-05T09:56:33Z")

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I’ve cleaned out my humidifier however whenever I used it the water ends up turning black, and I can’t figure out why. Could it be pulling stuff from the air? Thanks!

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**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\
**Post date:** [January 5, 2009, 12:15pm UTC](https://boards.straightdope.com/t/black-humidifier-water/479928/2 "2009-01-05T12:15:37Z")

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Some humidifiers use carbon electrodes to heat the water. They break down over time and leave black carbon in the reservoir.