I don't think this is possible but I"ll ask anyways...


Apr 16, 2009
Is it possible to keep a pygmy octopus in a 12gal nano with a protein skimmer. I"m not new to marine, and am interested in getting an octopus.

Currently empty 12gal is just sitting there. But from what I"ve been reading most of the "little" guys will get to big for this tank.

Am I correct in assuming it's too small??


Staff member
Moderator (Staff)
Sep 4, 2006
Twelve is a bit of a close call I think. I raised two together in a 15 hex with a couple of well healed large pieces of live rock, very shallow argonite sand bottom substrate, a skelter skimmer/filter and 30 percent water changes weekly without any water problems and the octos lived 11 and 13 months. The lone merc I put in the tank at 5 months also lived 13 months but I never failed to do the 5 gallon water changes and change new filters in the skimmer/filter como weekly. Alternately, I lost two after two weeks in an 8 gallon hex with a hang on filter, less live rock and no skimmer. On may have died of cold (the small chiller in the tank had an undetected problem and did not shut off) and the other of old age but I could never be sure. Both of the losses came to me as adults. I never had ammonia or nitrite showing in the tank.