[header] How to care for a crab [title] Obtain an aquarium tank. [step] Six crabs can live comfortably in a 3-5 gallon tank. Ensure the tank has a screen at the top to allow the passage of fresh air. 
If buying your tank secondhand, give it a good rinse and scrubbing with soap, and let it dry before placing your crabs in it. [title] Make the tank a crabitat.