white vinegar is what i use to clean scale build up. much nicer to use than other chemicals! so you put in i think a cup of vinegar and run it thru the regular cycle - i don't think you let it sit for that long. but then flush teh coffee maker with 2 pots full of water 9which you brew thru like you did the white vinegar).
and if you can, use organic coffee.
i would also suggest a french press which is what i have been using. boil water, pour over courser ground beans and then press grounds to bottom after 4 minutes. so yummy! and then i don't have to clean the coffee maker which i just put away since i stopped using it over teh french press!
enjoy!
J.