| Clue | Source | Date |
|---|---|---|
| Remove calcium deposits from | New York Times | 27 Jun 2021 |
| Remove calcium deposits from | The Washington Post | 13 Dec 2017 |
| Remove calcium deposits from | LA Times Daily | 13 Dec 2017 |
| Remove calcium deposits from | ||
| Remove, as a calcium compound | ||
| Remove deposits from, as a water heater | ||
| Remove deposits from, as a water heater | ||
| Remove, as a calcium compound | ||
| Remove, as a calcium compound | ||
| Remove, as a calcium compound |