Looking to get Octopus Vulgaris (common octo) Need recommendations on tank size

[Sensasian]

Hey, I'm looking to get a common octopus, they get above 3 ft. / 1 meter in length, need some advise on tank size? Have been looking at 150 gallon tank. Any other advise appreciated, Thank you!

 

[DWhatley]

That should do (this assumes an additional sump for hardware) for a US O. vulgaris as they are smaller than their European cousins. Do note that square would not be the best configuration as it will need length for spreading out. Sourcing a vulgaris, however, is difficult.

If you are looking at a Common Caribbean Octopus (O. briareus), even a 65 will be fine (again long, not square).