Girls, we've been doing it for 2.5 months, they don't drink water on t…

Girls, we've been doing it for 2.5 months, they don't drink water on the interval. We're on IV and need to give them something. They advised me to try a smoothie. If you made anything from what and how? I know that sugar can't be added. But how many dried fruits per amount of water? And who has done biolakt? I'm going to pick up the starter tomorrow, but I have no idea what comes next ??‍♀️