Oh ok, could be the feeding tbh, I feed mine 3 times a day and more on weekends with a large variety of food. Hikari gold, nls growth, homemade 'brekkie' food (with bacon and egg, think that's why they love it lol), beefheart, bloodworms, feeders (home-bred convicts and guppies) and crickets.
Ingredients for the homemade Breakfast food are spinach, bacon, eggs (make sure they're raw otherwise they make a MASSIVE mess when feeding, I learnt the hard way), some hikari, some nls, water and broccoli. Blend it up and freeze it. It literally gives them the best colour and gives them good growth, they have it for breakfast every morning. Personally I think it's all because of the bacon but you never know