Let's put it this way
Could you please give me some water No, that's too polite... The second sentence sounds to be correct. Remember that water is a non-count noun, meaning you can't really cuont it just like other objects (e.g. two sugar cubes etc) so you need to put something before that noun in order to make it more understandble. The same in Hebrew: We don't ususally say: תביא לי מים but rather say: תביא לי קצת מים This tends to sound better. Of course these are all tiny nuances, and evetually I suppose you'll be understood. אנחנו לא בוקים...