The tank needs time to grow the bacteria that turns nitrites to nitrates. Once you have nitrates, you should do a water change, but since you have the chaeto, this might change. You can feed the snails one of those waffers made out of algae ( if you are concerned about starving them). If any of them survive a couple of weeks, your tank must be safe for a fish. Maybe someone else can think about something else.
Nice job!
Nice job!

