my cuttles layed one egg and im not sure when it will hatch and what to feed it. can i feed it baby brine shrimp? or adult brine shrimp?

Don't know about hatch times (although water temp plays a role!) but brine shrimps of any sort are not great food! Not nutritious enough. As an EMERGENCY food you can feed newly hatched brineys (still have the yolk) or enriched adults, but you'd be better to lay in a stock of amphipods or mysids!

J

where can i get amphipods and mysids?

From your other posts this is a bandensis egg yes?

Righty has seen hatching in 3 weeks, but mine took about 5, so look at these for a rough guess ;)