hmm.. i've had a pool in my dream and glasses of water before.. a bit more on reading though.. i found that if i shift concentration.. even a "little".. by glancing or blinking.. the letters may distort and the page may go blank. I found though.. that because while i'm awake I usually visualize works when I talk.. its easy for me to do it in dreams. Some people may find it harder though.

Food is awesome though in dreams.. you gotta try it, I even had a dream where I took bites out of random people (and no, i'm not fat.. eating in dreams is just awesome.. just like flying)