• Looking to buy a cephalopod? Check out Tomh's Cephs Forum, and this post in particular shares important info about our policies as it relates to responsible ceph-keeping.

thinking about it


Jul 24, 2006
ok so im thinking about starting a little octo. tank. i now have a 55 gal mixed reef and a 5.5gal night stand reef.

the octo tank couldnt be that big im thinking maybe 25-30gal tops. so my biggest question is what species will do good in that tank size?!?

also id like to know what kind of filtration is best for octos?

is there something besides no open holes and the tightest lid ever that i need thats diffrent from anyother marine aquarium?

lastly can ikeep corals with an octo. i know stinging corals are a no no but what about soft corals? or will it just eat them? or poisinouse soft corals like zoas and some leathers. or is that just setting it up to get poisoned

nate :mrgreen:
:welcome: I'm not an octo keeper, but please read all the ceph care articles, and as many of the ceph care threads as you can. You'll find them at the top of the page. You will find answers to all your questions, and probably to a lot of questions you haven't thought of asking yet. Learn as much as you can before you really get serious about keeping an octopus. It requires an impressive outlay of cash and you want to do it right the first time.
In that small tank size I would get a cuttlefish (bandensis).

I currently have one cuttle in a 30 gallon with zoas, leathers and xenia along with a tridacna. Only problem is that when you have lighting nessasary for even soft corals, cuttles hide all the time and a octo would be much worse.

On a tank that size-remember 3 things-filter, filter, filter.
you can keep a small bimac in a 30 gallon. I dont know much about other species besides bimacs though. I usualy catch my own but you can buy them too. but make sure it is a 30 long not tall.

make sure hes got a good hiding spot in there.
for filtration

I recomend a whisper 30, and an air pump though cause they need airated water, and a protien skimmer is recomended by everybody here. but i believe that it is not completely essential, but if its your first octopus i would definately get one.

Please do not recommend tank sizes that really are too small for the octopus.

"you can keep a small bimac in a 30 gallon"

Well, last time I checked, most bimacs do grow, eventually. This is not enough water volume for the amount of waste an octo produces.
but its really not to small, you can, and there is plenty of water for the waste it produces. as long as you do your weekly water change and your filter and skimmer are running
Alex, at one time (2002) we advised at least a 30 gallon tank for a bimac, but then we discovered that it didn't always work out so well. Some bimacs outgrew the 30 gallon and the octo owner was left in a terrible position - not enough time to cycle a new, larger tank. Sometimes as the bimacs grew they overwhelmed the tank filtration system -it's not a solution to have to do major water changes every day. Also, the larger bimacs didn't have much room to move around in a 30 gallon tank. So, we now recommend a 50 gallon tank for a bimac.

It doesn't matter that it might be possible to keep a small bimac in a 30 gallon tank - we are advising people to buy a tank that will be sufficient for the entire life of their bimac. In the end, it's better for the octopus and easier on the owners.


just to echo on Nancy's post...

yes, please always make sure that you buy the right size of tank in the beginning. One reason we always now recommend 50 gals is because of how fast they can grow.

I have bought octopuses and cuttlefish and kept them in smaller aquariums until they go but not everyone has that luxury of another salt water tank already set up at the time. Moving an octopus to a bigger tank can be a horrendous experience too.

So, best advice with buying an octopus is to start out in the best way possible...

Get the biggest tank you can (even some bimacs can be cramped in a 50G), Get a skimmer from the start, get good filtration and most importantly, get some experience at looking after marine animals and water testing first!

soft corals like leathers are fine but the octopus can do them a lot of damage once its bigger.

oh well ya, When it starts getting to big of course move it to a bigger tank. I guess you should get one from the begining. I always just caught them as a baby and when it got to big let it back in the ocean and get another. Not everybody lives near the ocean and if you get an unusualy large growing octopus you could end up with a night mare trying to catch and move it. But if you live by the sea I would definately save space and mney and just go with a 30 and toss it back when it gets to big. Unless you grow to attached to him. But I dont think it very nice of us to force a creature into somewhere hes not comfortable being for his whole life. I only keep em for 6 months or so, otherwise i feel like ive given it a life sentence under house arrest. and no matter how nice(or big) your house is, Being stuck inside it your whole life would be inhumane.

so ya, anyways, go with the 50, theyre right.
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