HI Evan,
When you say "baby" how old are you talking?
The BH mix you feed,is it cleaned well of any connective tissue and fat? Does it have any shrimp shells in it? Most likely causes of the bloat are eating something undigestable like these things or eating spoiled food left inthe tank. Are you wiping down the tank real good and maintaining good water quality...blended Bh mix will foul the water quickly if you slack on water changes.
How many babies are in the tank?
al
ps..ditch the melafix...its not useful for anything .