[header] How to take care of a purple thai devil crab [title] Get an aquarium tank. [step] Purple thai devil crabs live near rivers in the wild. To keep your crabs happy and healthy, keep their tank as close to the natural habitat as possible. 
Purchase an aquarium tank of at least 5 gallons to accommodate your crabs. [substeps] Find a tank that will fit with the number of purple thais you have.