I use a 1kg plastic peanut butter jar (after the peanut butter has been finished of course) :lol:
Drill a hole in the lid big enough for some airline tubing to fit through. My husband made a wire frame that fit around the neck of the jar then hooked over the side of the main tank so I didn't need a separate tank, it just floated in the main tank.
Thread the airline through the hole in the lid and add an airstone to one end and attach it to a small pump at the other. Half fill the jar with water and a bit of salt (am trying to remember how much I used, it is ages since I have hatched them) and add a blob of brine shrimp eggs (about 1 tsp if I remember right). Screw the lid on making sure the airstone is well down in the jar. Turn on the pump and leave it floating in the main tank until the eggs hatch (varies depending on temp).
To harvest, turn off the pump and wait for the water to settle then siphon the shrimp up with a turkey baster. You can see them shimmering in the water at mid level.
I would squirt them into a white hanky then give them a quick rinse in fresh water before feeding them to the fish.