Steve, I know there is a fish food that has some antibiotics in it. From my very basic understanding, I believe the downside risk is that the fish could become susceptible (sp?) to other infections due to a reduced capability of their immune systems caused by the antibiotic.

I'd like to keep hearing about what you discover.

I can find out the brand/name of the fish food if you desire.

Excerpt from Robert Crais' "The Monkey's Raincoat:"
"She took another microscopic bite of her sandwich, then pushed it away. Maybe she absorbed nutrients from her surroundings."