goldfish are a really poor food choice for saltwater predators. I'd recommend NOT feeding goldfish.
there is a lot of information on reputable saltwater hobby sites about this. just doing a quick search, I found the following:
article:
http://www.wetwebmedia.com/goldfshfd.htm
to add to that reference, here are a string of FAQs from wetwebmedia regarding the feeding of goldfish to marine predator fish:
http://www.wetwebmedia.com/feedrfaqs.htm
There is a lot of information available on other sites as well (including this one). I am referring to WWM because I knew where to find this info.