# what is that stuff that collects on your sink?

**URL:** <https://boards.straightdope.com/t/what-is-that-stuff-that-collects-on-your-sink/154288>\
**Category:** Factual Questions\
**Created:** [February 11, 2003, 4:22am UTC](https://boards.straightdope.com/t/what-is-that-stuff-that-collects-on-your-sink/154288 "2003-02-11T04:22:44Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![ely2121](https://avatars.discourse-cdn.com/v4/letter/e/bbce88/32.png) [@ely2121](https://boards.straightdope.com/u/ely2121)\
**Post date:** [February 11, 2003, 4:22am UTC](https://boards.straightdope.com/t/what-is-that-stuff-that-collects-on-your-sink/154288/1 "2003-02-11T04:22:44Z")

</div>

What is that weird white chalky looking stuff that collects on your bathroom sink? I think it comes from the use of toothpaste but I am not sure. Does anybody know what causes it and does anybody know how to prevent it from happening or how to get rid of it? It really bothers me. Any help would help much. Thanks:confused:

---

<div class="post-metadata">

**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\
**Post date:** [February 11, 2003, 4:28am UTC](https://boards.straightdope.com/t/what-is-that-stuff-that-collects-on-your-sink/154288/2 "2003-02-11T04:28:47Z")

</div>

It’s probably calcium and other minerals in your water. Do you also have this on the tap where the water comes out? What about on your shower head?

---

<div class="post-metadata">

**Author:** ![SnugTheJoiner](https://avatars.discourse-cdn.com/v4/letter/s/e8c25b/32.png) [@SnugTheJoiner](https://boards.straightdope.com/u/SnugTheJoiner)\
**Post date:** [February 11, 2003, 5:16am UTC](https://boards.straightdope.com/t/what-is-that-stuff-that-collects-on-your-sink/154288/3 "2003-02-11T05:16:01Z")

</div>

It is grahdoo. (Pronounced grah-DOO) Surely you know what grahdoo is?