500ml lucozade sport in the mornings
Then I top up that bottle 3-4 times a day at work
Then 2-3 pints at home in the evenings
So I generally fluctuate between 3-4 litres a day
You need more if it's hot of if you are excercising as well.
I only really started drinking more water when I started working after highschool, and I definitely feel better for it.
Only problem is that if I don't drink, I get thirsty quicker than people who drink less on average
My gf drinks almost no water, doesnt like plain water, so usually drinks fruit juice (which is ok, if a bit pricey) and fizzy drinks (which don't really help much).
As such, her blood pressure is low, and she needs lip moisturiser very often.
I'm trying to wean her onto the water thang