You already have another thread on this basket star, do you not? Please see answers there. I suggest, along with the other poor choices your LFS sold you (no doubt made a pretty penny) that you return it, and find another store.
Brine shrimp alone is nutritionally poor, and is not a sufficient long term diet. You must enrich the brine, as well as supplement with other things (mysis at the very least). Generally you should feed them after dark.
That is, BTW, a baby.