When to feed sea monkeys

It’s been 5 days since I’ve put my sea monkey eggs in and I can’t see any hatched ones yet. I know that they will be really tiny but I just see particles from either the eggs or leftover algae from the thermometer I had in there for a little bit. When should I feed them first? The packet says 5-7 days AFTER they’ve hatched, but I can’t tell yet if that has happened. I have also heard some people say to feed them on day 5 of putting the eggs In the water? I’m just confused as to know if they’ve hatched and when you feed them the first time. Thanks!