yeah 100% escape proof, no holes, no hoses without a super secure screen, lots of hiding places (live rock that has been cured), and i think the most important thing is that they eat crabs so get a bunch before you get the octopus. Another thing to think about is that they have a relatively low survival rate in captivity...an author in TFH had an octopus that lived 8 months i think and then it gave birth and died to feed its young.