If it is a food, it is probably an antibiotic laced food. The problem with those foods is the fish that need the antibiotic are generally off their feed, and not interested, to they don't get the antibiotic needed. Topicals or injectibles are much superior when antibiotics are needed specifically treating the affected fish. Antibiotics that are not consumed are being used up in the killing of good bio filter bacteria as well as any water borne bacteria.
Zone 7 A/B
Keep your words sweet. You never know when you may have to eat them.
Richard