Hi Fishgirl
They must be cutie pies, you will have to post some photos!

It seems since they are just lil juveniles they are used to eating the brine shrimp that the breeder has been feeding them since birth. Getting them to like something else is going to take time. If they are eating the blood worms too, that is great. I would cut up the tiny blocks of bloodworms for them, since they can be a bit big for the babies, but if they are eating them fine, then great..
It will just take time to slowly introduce them to other foods. Mine as I posted earlier never took to freeze dried foods. You can try scattering some flakes along with the brine shrimp, and they may eat some of the flakes along with the shrimp and find they like it. But it will take time and I would think that for now, at least the brine shrimp and the bloodworms is good for them.
cant wait for photos!

~ kate