i feed them newly hatched brine shrimp, for example, these 30 fry are going to consume more and in less time if placed on the breeding trap. Finding bbs in the large tank is much more difficult for the fry, since the food particles as well as the fry are present in much less density.
It is more time consuming and often yield sub-optimum results. With this approach, you are likely to end up increasing your maintenance requirements in the form of siphoning waste, cleaning filters and replacing water. 1,000 newly born fry in 5-gallon may be the optimum fry density for feeding purposes. How feasible these rearing densities are in practice, and what sort of systems are better suited are the real questions.
8)