Good afternoon. Here is the pertinent info for fish food:
FISH Fish food and vacation blocks often contain chometz. Tetra Tropical Slow Release Gel Feeders (Tetra Weekend 5 days, and Tetra Vacation 14 days) are acceptable. Goldfish and Tropical fish can be given tubular worms, frozen brine shrimp, and freeze dried worms (if they do not contain fillers).