Just make sure your octopus won’t be able to escape. They are strong, smart, bored, curious, and fit through gaps only a little larger than their beaks. They pull hard on tubes, push hard against tops, and will go for a walk behind your couch or get into your overflow box if they can. Think everything through and secure everything
My tank has done very well. I successfully kept a Caribbean Reef Octopus from very nearly a hatchilng until she laid eggs and brooded last year, and kept an older Caribbean Reef Octopus the year before. I've had great luck with KP Aquatics for obtaining Octopodes and other saltwater fauna, and they have been stellar in customer service as well.