After active treatment, I am a believer in the "we are slightly overdoing it" theory with water. Tea and coffee do add to your intake, the diuretic effect is pretty weak. Skim milk counts too, as do broths and fruit. Drink when you are thirsty/sweaty, drink when it's hot. Melbourne has great tap water, so don't add to the plastic waste and buy bottled water, refill an existing bottle for free. I'm just not sure one needs a water bottle in hand on a 15 minute tram ride.