Giant octo In New York with cuttle


Aug 4, 2005
This octo was in a chilled aquarium. The tank seemed rather small for such a large octo. The tank was about 250 gallons


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Wow, nice octopus!!

Yea, iv noticed a lot that many aquariums housing giant pacific octopuses have tanks that are a little too small for them. Im guessing they are really saving money or trying to save money. Who knows. I wish my giant octopus lived closer to me..I have to go like an hour and a half just to see it:sad:
This might be a weird question - but what happens to the octopus when you put it in too a small tank(other than the bioload problems)? Does anyone think it bothers the octopus?

If the octo is well fed and has an enriched setting, will it show different behaviour to being in a larger tank?

Obviously the bigger the better, but its quite hard to tell what an octopus is thinking about,
big octo in small tank

this is completely hypothetical, but this thread and others about large commercial aquariums that seem to keep GPOs and other large octos in small tanks got me thinking: one major difference between big aquariums and home tanks is that most aquaria have seawater piped in, and are constantly getting complete water changes. One reason TONMO recommends large tanks for cephs is the bioload, and it would seem like an open system that uses constantly renewed seawater would eliminate this issue entirely. Of course, perhaps the octos are feeling "cramped," but that's a harder call-- most octos seem to like small, enclosed spaces and little tidepools, although they also like being able to leave these hiding holes to explore... but perhaps they're not so unhappy in a small space if someone is bringing them food, and they always have fresh seawater?

Certainly, it is in the aquarium's interest to have a small enough tank that the octo is visible to the visitors, too, although it'd be a shame if they cause the octo to be cramped or otherwise unhappy just for this...
You make a good point Monty,
one major difference between big aquariums and home tanks is that most aquaria have seawater piped in, and are constantly getting complete water changes.

Even if they don't have sea water piped in, they probably have several exhibits piped together and filtered with a large filtration system, so the total volume of water is quite large compared to the average home aquarium.

I was also thinking that once an aquarium is built, the size of their exhibit tanks don't change (unless they renovate). The exhibit space may have been originally intended for a different animal, but the aquarists may have acquired a cephalopod and just found a place for it in their aquarium.

Just my :twocents:
So ***technically*** if I had a skimmer that filtered for 400 gallons and a wet/dry custom made with 40 gallons of bio balls in wet and dry sections(30/10), and had nothing else in a well cycled tank. Dolphin 2100 ampmaster pump (up to 35 gpm) to dial in what ever flow rate I needed, and a chiller.

I could house a GPO in a 240 gallon (48 inch x 48 inch x 24 inch) with a 60-90 gallon sump?

live food, squeeky toys, lunar lights, and escape proof.

Doable-or not?
Thats why this is an interesting topic - I doubt there is any "data" about things like this, so it probably comes down to peoples perception and common sense.
I was thinking the attention lavished on a well loved octo in a smaller tank might make a happier octo than one in a lonely but larger aquarium tank.

I cant say I'd be too keen on feeding a gpo :biggrin2:

If it were me, I would give it a go, and see whether I think the octo seems ok with it - and if not return it to the sea. Of course in NZ 90% of the population is within 30mins drive of the sea - making it much easier.
GPO's need large tanks. An 800 gallon tank is not uncommon because, as you know, they grow quite large! And yes, providing food would be difficult - I believe the one at the NRCC eats several large crabs a day.

I suppose its a bit like puttin a chicken or dog in a cage and sayin well you can breath, you can stretch an half pick up a bit of pace by running before you hit the otherside, but hey you've got loads of toys to play with.

But then those animals dont squeeze themselves into small spaces like octos.

Although saying that an octo likes to jet swim....
Theoretically a smaller tank with piped seawater should be OK for an octi............but a lot of the waste ends up on the floor and in the aquascaping, so eventually there will be bioload problems even in an open system. We have a biggish tank and we're careful about the size of octopus we put in (and it's an open system) even with careful daily siphoning, once a week we drain the tank to knee level and climb in to clean and it can be pretty yucky, with anoxic black sludge in out of the way corners, once a month (or so) the tank is completely drained and cleaned (ick!).

The other problem I can see is that octopus can be very active and a large octopus in a smaller tank will sustain much more injury (butt burn and other scrapes) than it would in an appropriately sized tank.

My :twocents:

Yes, I've been to the Dallas World Aquarium (Colin has, too!).
I think the tank is 800 gallons. It's a tall tank, as are many of the octo display tanks.

It's been more than a year since I've been there - they have far too many anemones blocking their octos path - it would get stung for sure. I called many times to talk to the head marine biologist about this - she was never in and never returned my calls. I got the impression that this facility was much more interested in their rain forest and other exhibits than in their octopus.

I believe the Dallas Aquarium at Fair Park has a GPO and at times has had blue rings, if you're interested in seeing more. (Check first, to make sure!)

The Tampa Aquarium has one in a tank that is about 3 feet deep, 4 feet tall and 6 feet wide. Quite a few anenomes too. I have read that the Seattle Aquarium uses 300 gallons for GPOs.
Why would they want a tall tank for GPOs?
yes, I used to volonteer there, and i have to admit, the rainforest exibit was their first priority(also their main money making attraction). being privately owned i dont think calling would change anyting. b/c they do have two anatalin* manatees in only a 30000, as well as a handful of arapiema*
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