Wow. I thought I responded. Hmmmm.
Anyway-
The aquarium is empty now. It will be set up just for the octopus. It’s 110gallons and a traditional rectangle shape.
Mangetout and Speaker- You two are a riot 
Don’t Fear the Raptor
An Octopus in the Home Aquarium
By James B. Wood
http://www.dal.ca/~ceph/TCP/octokeep.html
Wow. Who knew that tenticle porn had classical antecedents?
The Japanese are such nice people! 
Warning; Even if you take care of it perfectly, your octopus will not live long. 3-4 years is a good life for a healthy octopus. If you get attached to it, you’re going to lose it soon.
Sounds like a bad idea for a pet, but very interesting info. I had no idea they were so smart which really makes keeping it in an enclosed aquarium pretty cruel sounding. A fish I can see, it probably has no idea its even in a closed space, but if the creature can understand it then it must be a particularly cruel brand of treatment. I wouldn’t live very long in an enclosed space either.
You’ve got me very interested in this, and I just spent an hour looking at photos on the message boards at this place.
Might give you some useful information.
Well, I wouldn’t recommend the blue ring octopus even if they are hella cool looking.
From this (http://www.barrierreefaustralia.com/the-great-barrier-reef/blueringedoctopus.htm) page:
"With a beak that can penetrate a wet-suit, they are one little cute creature to definitely look at BUT Don’t touch.
The bite might be painless, but this octopus injects a neuromuscular paralysing venom. The venom contains some maculotoxin, a poison more violent than any found on land animals. The nerve conduction is blocked and neuromuscular paralysis is followed by death. The victim might be saved if artificial respiration starts before marked cyanosis and hypotension develops. The blue-ringed octopus is the size of a golf ball but its poison is powerful enough to kill an adult human in minutes. ***There’s no known antidote. ***The only treatment is hours of heart massage and artificial respiration until the poison has worked its way out of your system.
The venom contains tetrodotoxin, which blocks sodium channels and causes motor paralysis and occasionally respiratory failure. Though with fixed dilated pupils, the senses of the patients are often intact. The victims are aware but unable to respond."