leave the fry with the parents for as long as you can... the fry feed off the parents slime coat.. so you really have nothing to do.. after about 2 weeks start throwing some small food in there.. decaps brine, or frozen baby brine.. this will help the parents keep up with the demand of the slime coat... on the 4th week I would get ready to pull them,, they should be big by now, and eating like crazy.. near the end of the 3rd week, or the beginning of the 4th watch out for sores on the parents sides.. if you see it, pull the fry right away.. the parents aren't producing enough slime coat, and the fry are eating the parents flesh.. and you don't want the parents to catch anything, and die...
andy