29g is way to small for an octo, even a small species.
i'm glad you posted that, i wasn't sure if we were really talking about a 29g tank.
History has told us time and again, an octopus needs 55 gallons+. Depends on species, but our general rule of thumb has been, better safe than sorry 55 gallons and up. In many cases 55 gallons will not do, either.
My question to you guys is "does 6 US gallons make a difference?"
Yes it's a 29gl biocube and if you read the entire first post, I have a total of 49gls with a custom sump. Or were you referring to a med size octo in a bio29?
Currently the merc is in a 10gl and doing very well. 24/7 food source and I am checking params every 3 days.
For the mediums sized species we keep, a 55 with sump (or larger) is definitely strongly recommended. HOWEVER, a 29 gallon is a GOOD size for dwarfs (even for a pair of mercs, I have raised a pair in a well filtered, often water changed 15 very successfully - the largest I have used for mercs is a 45 and kept 3 of them in the same tank with lots of live rock). A 55 gallon tank is really too large for a dwarf species unless you are trying to keep a small community. A single dwarf in a 55 would never be seen and there would be no way to ensure it was eating. A 29 is also quite appropriate for a baby octopus of a larger species. As the hatchling grows larger, it would then need to be moved but the smaller tank is preferred while they are young for the same reasons it is appropriate for a dwarf.
Wow that is awesome. How long did you house them and what size were they at their biggest?