You can remove the tube from your reservoir at any time. A shut-off valve on the reservoir side closes as you disconnect, so the water in your reservoir stays put.
Close off the tube. Pinch the tube or close the bite valve so the water in the tube stays inside.
Raise the tube. Hold it upright above the reservoir so the water in the tube doesn't run out.
Disconnect. Press the release button on the connector and pull the two halves straight apart.
Tip: A few drops may come out of the open tube end. Disconnect over a sink or town to catch them.
To reconnect: Push the two halves together until you hear a click.