Personally i probably wouldn't bother with the brine shrimp culture... at 1" they grow pretty darn quick and will quite possibly outgrow wanting to eat brine shrimp, not to mention, there are "easier" solutions...
I for one feed my fahaka the following (although i know there are other foods that also work):
As a smaller puffer 5" and under: Blood worms / smaller pieces of defrosted scallops from market / Cherry red shrimp i was breeding at the time / pellets / defrosted shrimp from market / Small snails
After about 6" or so i used the above along with: Mussels (on half shell) / Live Marble Crayfish i was breeding / Clams in Full Shell (although at the beginning had to help crack it open to make life easier till she could tackle them alone)
The fact they are so aggressive i guess also helps in the aspect a little since they are willing to almost bite anything at least once...