Yes, it is safe to use still. Pinkies and fuzzies don't have as much calcium as you might think. Their bones aren't fully developed. I'm not sure how much calcium the fish have. It probably varies by species. These frogs need a lot of calcium to develop properly. Even with your varied diet, supplementing with calcium once or twice a week should help. Pacs can develop calcium deficiencies at any point, not just when they are babies/juveniles.