They are new fish. I bought them 4 days ago. I am currently placing them in a quarantine tank. My main tank is cycled. The water from the quarantine tank comes partially from the main tank, the other is dechlorinated tap water. The filter is also mature.
I'd switch from flake food. Daphnia, bloodworms and brine shrimp were all gobbled up by mine. Maybe they will accept flake food eventually. You could feed it at the same time as another food they will eat and I'd think they'd eventually catch on to the flakes.