Log water intake in the app

First, click the orange plus at the middle bottom of your screen.

Next, click the "Water intake log" option.

Then, either type in how many oz you drank, or choose one of the options provided (7 oz, 11 oz, or 17 oz). The date and time will automatically pop up as the current time and date. If you are logging something from earlier in the day, you can always change those if you want to.