• 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.

Should we fear the INK ?!?!?

The Gnome

Feb 5, 2006
I was just wondering about the effects of the O. bimaculoides in a closed loop filtration system ? I was planning on constructing a 125 gallon aquarium with a 55 gallon sump with one or two 'bimac' specimens living in there together. Are these animals easily startled ? What affects might they have on all the live rock and other life in the system... not to mention the skimmer and refugium ?

I would really appreciate any feedback on this ink issue, it's plaguing my mind !:bugout:
Hi and welcome to TONMO.com! :welcome:

My bimac inked about 4 times in her lifetime, although I was careful not to startle her. The ink is removed by the protein skimmer and to a lesser extent the carbon. A partial water change can help, too. this

It doesn't seem to bother the live rock and the only other life you can have there will be crabs, shrimp, maybe a small brittlestor or urchin.

We've had a number of people try to keep two bimacs in a large tank and has not worked out well ever. One bimac becomes dominant and the eventually you have only one octopus. - don't try this!

Thanks Nancy. How long did your bimac live and what size enclosure did she live in ? I'm surprised and honestly relieved to hear that your bimac was able to survive her ink, because that was the last factor in my decision to become an owner. Should I get a beefy protein skimmer just in case that happens to me ? Did you have a closed filtration system ? Could you refer me to a site where I could learn more about this specific species ? ( O. bimaculoides )

Also, I was thinking of having some other animals living in the sump/refugium below the actual den of the kraken, in the case of this inking, what would you suggest to keep in the bottom ? Nothing too sensitive, like a reef or something - but maybe an eel could survive that with an emergency water exchange ? I plan to buy a RHO water purifier with deionization capabilities so that I can keep new water on hand in case of such an emergency.

I really hunger for more knowledge on this subject !
We have lots of octopus and even bimac information right here on TONMO.com. Just click on the Ceph Care button above. I'd suggest Colin's Equipment List and my Checklist for starters. Also the Bimac Care Sheet and Carol's article on Ink, her bimac.

You might look at the thread entitled List of Our Octopuses at the top of Journals and Photos for a list, complete with names, of bimacs and other octos we're keeping and have kept.

My bimac lived about 10 months in my tank - I had a 46 gallon, we're recommending at least a 50 gallong now.

Yes, you'll need a good protein skimmer!

Thanks a lot Nancy for your insight ! You've been very helpful and inspirational to me. I'm sure it will be a while before I have everything I need for the care of a bimaculoide, but by then I should be an expert from the wealth of knowledge available on this site.

Thanks again !

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