I’m doing a study of gut microbial interactions with cancer treatment, so I need to remove their normal gut microbes. I’ve tried giving the mice antibiotics in their drinking water but they won’t touch the stuff, leading them to become dehydrated. I want to supplement their water with Ribena To sweeten the water and encourage them to drink the antibiotics. What concentration is appropriate? Is there a ‘goldilocks’ concentration I should be aware of (i.e., too much makes the mice sick, but too little is pointless)?