You need to add a small amount of the dry brown eggs (like a powder) to some salt water.
Get a 2 litre plastic drink bottle and cut the top off and half fill the bottle with salt water. Get a hydrometer from a petshop to measure the salt level. You want the salinity about the same as sea water but it doesn't have to be exact. It doesn't have to be perfect and any salt (except iodised table salt) will work. I buy a bag of swimming pool salt for brineshrimp eggs because it's cheap.
Add some eggs to the salt water, aerate well for 24-48 hours and then you should see little orange things in the water. The orange things are the baby brineshrimp and they are called nauplii. The eggs hatch faster in warm water. We had an aquarium set at 28C and had the hatching containers in that to keep them warm. But you can leave the container anywhere as long as its not too cold. Most people have them on top of a tank for warmth.
To harvest the nauplii, remove the airstone and let the container sit for a few minutes. The brown eggs will either sink to the bottom or float on the surface. The nauplii like light and gather wherever, usually near the top or bottom. Use the eye dropper/ turkey baster to suck some out and add them directly to the tank.
The small amount of salt water going into the tank will not harm any fish.
Start a new hatchery every day or two, and use up the nauplii within 48 hours of hatching for maximum nutrition.
If the eggs are old they could be stuffed and no longer viable. Try to buy eggs from a place that keeps them frozen or refrigerated. And keep your brineshrimp eggs in the fridge too.
