little and often is best. 2/2.5 is the minimum for LT and as far as I am concerned that includes coffee and tea (not shakes, i think, but could be wrong). basically if you have 2litres of plain water (still or sparkling) every day you will be fine.
If you have it in big amounts you're more likely to wee it straight out, i always think. and you can drink too much and flush out the nutrients, apparently.