How many crabs are you getting and how big is the tank you'll be keeping them in?
I'm not an expert by any means, but I've heard a general rule is 3 gallons per crab (could be junk, I read it online while researching to see if I could get one, I couldn't 😞
They do need access to air, cannot be kept totally submersed. Also you'll need a lid for the tank as they'll try to escape! Seems to be a problem with all crabs/crayfish!
Fish are fun!! 🐡🐠🐟