Well, I'm not an expert on fishless cycling, but I have heard from others on this forum that I've grown to trust that fish food does not convert into ammonia very well. You're better off using an uncooked shrimp from a grocery store. That is a much better ammonia source than fish food.
Fish food might work, though, so keep testing for ammonia, nitrite, and nitrate. If it were my tank, I'd go get a shrimp, though...
Good luck!