Brine shrimp are an excellent source of protein for most small fish.
They are mostly used within the first 48 hours of hatching as the eggs sack is high protein.
After 2 days it is recognised that adult brine shrimp are only as good as their last meal ( stomach contents )
I raise a fresh batch of baby brine shrimp every day . Most of my adult fish will hunt them down. But cost wish it is a live food more suited to encouraging breeding and an essential food for some very tiny newly hatch fish.
What species of fish do you have?
There are many other live foods you can culture but I guess sea monkeys are more fun for the kids than grindle worms.mirco worms, white worms or wingless flies LOL.
I would encourage feeding any live food. Mosquito larvae are something the kids can watch fish hunt.
A strainer is used to remove the salt water from brine shrimp. Coffee paper works but a strainer will have you heading in the right direction.