Pour water up to a visible mark

Pour cold water into a clear glass up to the mark, then pour it back. One round per clip.

Start: A jug or bottle of cold water and an empty clear glass or cup with a mark on it (a printed line, tape, a rubber band or a marker line), both in view.

Record: Point at the mark. Pour until the water reaches it, stop and put the jug down for a second. Then pour the water from the glass back into the jug and put both down. If you pour too much, keep recording and carry on - that clip still counts.

Done when: The glass is empty again and both stand on the table.

Also counts: Any jug, wide-mouth bottle or carton; glasses of any shape and width; either hand. Cold water only. Send as many clips as you like, changing the glass, the mark or the jug each time.

How: phone on your head (not on your chest or in your hand), both hands free and in view the whole time, good light. One continuous clip of one complete round, about 10-60 sec (max 90 sec). Start recording a few seconds before you begin and stop a few seconds after you finish. Keep the app open until it uploads. Keep faces and documents out of view.

Can be declined if: not first-person, phone held in a hand, hands out of view, the start or the result not visible, the round not finished, or too dark or blurry.