Usually they can go directly from 1 fuzzy to 1 hopper. However, there is no problem with going to 2 fuzzies for a while. Lots of people will do that if they have some extra frozen fuzzies to use up. Also, if you happened to have a batch of small fuzzies, and then get a batch of big hoppers, it might be better to go with 2 fuzzies to sort of bridge the gap. Another possibility, if you have been feeding 1 fuzzy/7 days, is to start feeding 1 fuzzy/5 days.