Hi there... I just joined this forum. I have been doing a lot of reading about octopus on the net lately, and I keep ending up back here. I am not at all new to keeping a salt-water aquarium. I have a 90 gallon reef and I just bought and set up a 12 gallon NanoCube tank. Originally I planned to use the NanoCube for sea horses, until I noticed a Bimac octopus at one of my favorite fish stores. The octopus that they are calling a Bimaculatus is really small, it's mantle is smaller than a grape. I'd guess the tenacle spread to be about three inches. All they could tell me is that they have a short life span, which I was already aware, and that it won't get much bigger. My first question is if it is a Bimac, how much bigger will it get? Second question is, I know identification is tough, is there a way to positively identify a Bimac? And last, I know that a reef tank is not the best place for an octopus, and I fear that this 12 gallon NanoCube is too small, what size tank do I need? I really want a Bimac. I am really thinking about getting one of the little guys for this 12 gallon. I have gone so far as to set it up with water and filtration from my reef tank, so that it is established. I also stole two chucks of live rock from my reef tank, one of which has a big opening and seems like it would be a wonderful den. Right now, the only reason I hesitate is the size of the tank. I keep thinking that because they are so tiny right now, I'd be alright for a while.