What you want is BABY BRINE SHRIMP - not the frozen stuff or dried stuff which is ADULT brine shrimp. Adult brine shrimp contains very little nutritional value for fish and the frozen and dried ones are no more than exoskeleton.
In Singapore, LFS sell newly hatched fresh baby brine shrimp but here in Malaysia, your best bet is to buy the cysts and hatch them yourself. Instructions on the bottle when you buy the artemia cysts.