Bangai fry

[Maddy]

Hi guys. I have 23 cardinal fry. They are now 2 months old. Should I have started them on other foods already? The one or two times I tried with frozen cyclops the did not look very interested so I carried on with bbs. One thing bothering me though is a few babies are swimming or actually kind of bouncing up and down. What is causing this? The others are swimming normally. Could I also please have tips on how to get them onto other foods?