Goldfish are the absolutely worst thing to feed a SW fish, especially a puffer (& even FW fish, IMO):
http://www.**************.com/forum/library/feeding/feeders/
Feeding puffers: http://www.**************.com/forum/library/feeding/feeding-your-puffers/
http://www.**************.com/forum/library/feeding/feeders/
Feeding puffers: http://www.**************.com/forum/library/feeding/feeding-your-puffers/