I've kept Octopods before, worked for a Zoo in the Reptile/Aquatic dept. They really aren't too hard to keep. You must keep a secure lid on the tank though or they will get out and then die, drying up into a gooey little ball somewhere in your house! I used the white "eggcrate" stuff for a lid, that way they can stick their arms out and grab your fingers etc but still can't get out of the tank. Be aware they are very strong and will move items in your tank, unplug airlines, remove powerheads, disassemble any water lines that are not secured VERY WELL. I have never seen one release ink into a tank but it can happen. We kept ours in tanks that were about 45 gallons. Only one per tank usually or there will be a death in the family!