It can't be some mysterious way to do it, i believe the only reason for so little amounts of people doing it is because there is really not a lot of people who have a tank only full of larger mature caribe. And also one of the breeders i've heard about only has like 5 caribe in a 100 gallon, so i don't think tank size matters. It's probably simple as this if you get lucky enough and have a male and female in the tank and there tank conditions are good and they are feed enough that should be all it really tanks.