Hi, I recently fell victim to an impulse buy ( sorry couldnt resist). Anyway, it was a Blue Lobster/Crayfish. It is about 2 and a half inches at the moment but just yesterday shed his skin. I have him in a 18 gal tank with Ghost Shrimp I'm looking to re-house as I have since been told they are not good for each other. I am going to turn this tank into a sand substrate over the weekend and put a lot of rocks in it. My question is this. What can I put in there with him, if anything? I would really love to have another couple of anything in there. Also are they ok to keep in a tank in numbers of more than one. I would have bought 2 but when I was buying it there was only two in their own tank and one only had one claw, I didnt want to chance it. Thx.