So lets look all the required parameters to raise brine shrimp to adulthood.
Water: We'll need a hydrometer to ensure we maintain the correct salinity. Use sea salt if/when mixing. We'll also need some kind of filtration or water changes as required to ensure decent water quality - above all, do not overfeed!
Oxygen: An air stone on very low at one corner of the tank.
Food: real or powdered algae, brewers (or active?) yeast, some say wheat flour and (powdered?) egg yolk may be used. Brine shrimp are filter feeders, so they do not have mouths that chew.
The food will be key in producing a nutritious shrimp for our fish.
It will be about 4 weeks from hatching to maturity. Under good conditions, they might be bred to produce a near endless supply.
Having written the above, I saw a youtube video where a fella hatches brine shrimp and puts the contents in a bucket outside where it gets morning sun, covered with florescent light plastic cover and feeds with dried algae (no air stone, no filtration). He rotates a few of these buckets and periodically nets adult brine shrimp to feed fish. Although seasonal, his process seems pretty effortless. The (morning) sunlight affords warmth as well as promotes some natural algae.
I have often wondered about the extension of the hobby that raises live food for fish. Brine shrimp, daphnia, worms... Long ago, I hatched brine shrimp for fry and did grow some to adulthood using yeast, but these days I buy frozen and it always creates a feeding frenzy