You should be collecting dark, thick water... almost like watered down coffee. If you are pulling out what seems like watered down tea... you need to adjust the cup higher so that only the thick stuff comes out. Everyone has different amounts coming out per their specific tanks... so it's hard to say how much you "should" have. If the clear water fills the cup, that means that it is too low, and that all the regular water is merely dumping in... not good. Won't damage the unit at all... but you want the liquid to be thick.
Should smell to high heaven.
Rich creamy goodness that was once in your tank.