NO!!!!!!!!! I DISAGREE!!! You MUST get one smaller, because it is possible that since it is alone that it is a female already, and if you get one bigger it will probably be a female also, and they will fight to their deaths!! And, once they are female, they CANNOT change back!! So be SURE to get one SMALLER so that way it will most likely be male and they'll pair up and live happily ever after!!