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
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...
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.
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.
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
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.