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my new 10 gallon octo setup

Oct 30, 2006
any advice on weather or not a 10 gallon is big enough for a 3-4 inch carribean octopus. the tank water is from a 1 year long cycled reef tank, with good, but not perfect water quality. for filtration i have a power filter made for a 50 gallon, it is a hang on. i will be adding antic blue lighting also. the tank contains about 15 pounds of live rock. i posted a pic of the tank.

Thanks keithohlin


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Not even close. The problem is not that the octopus can not fit into such a tank size, (they can) but that the waste generated can not possibly keep up with a filter, no matter how large a system it is meant for...there just isn't enough water.
I have kept dwarf species in tanks as small as 25 gallons, and had them do "o.k.", but when moved into a larger 55, they really had a blast moving all about the tank.

Could you live in your bedroom for the rest of your life? Probably...but it sure would be boring!

I don't mean to sound argumentative Greg, but assuming you refer to O.mercatoris as the pygmies you speak of, 25 gallons is more than adequate. I have kept one in a ten gallon with no problems, however I did upgrade to 15 gallons due to the temperatures swing in my drafty old house. When I was rearing O.mercatoris I would use a divider in a ten gallon tank to house 2 juveniles, they did not seem bored with enough mental stimulation. In my experience 10 gallons is sufficient for o. mercatoris, o. joubini however, should really have about 20 gallons as a minimum.
I agree, a twenty five gallon tank is fine for a dwarf species...but, watching how much happier they were in a larger tank, I try to recommend that they be housed that way.:smile: