If they are in good health you can just give them each a quick dip in the freshwater pool before placing in the main tank. If any seem ill or you just want to be extra careful, you can set up an ISO tank for the new crabs. Give them a chance to fill up on good food, extra shells, and to molt before placing them in the main tank. It's up to you. Good luck and I hope you'll share pics. It's awesome you're choosing to adopt!
