Depends on what sort of "blackcurrent" you add? If it's a sugar based cordial it could make your water into a little snack and times that by 20 could give you 100s of extra calories a day. Even sugar-free low calorie cordials have calories and these can all add up. You can still have these drinks but with the CC diet you need to write it down and add it on to the total for the day. But if it's calorie free then that's fine.
I agree that water's boring & I never drink it (unless swallowing an asprin) and only have tea. It runs through my veins.
