• 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.

Tank Setup?


Mar 5, 2004
Ok guys im new to salt water tanks. Im getting a 120 gallon soon and i have a few questions about inhabitant selection. Here is what i want

Blue Ring Octo
Lion Fish
Snow Flake Eel

Now the big question is, can an octo live in harmony with these animals? And also what kind of fish would i put able to put in this tank that wont get picked off? Advice would be much appreciated.
Hey bad news, the eel mightt go for the blue ring, and kill it which also might result in the death of the eel. A large lionfish like an adult volitans could snatch your octo if it gets spotted. They all eat about the same food, competition will be unavoidable.

Blue rings as you know are highly venemous, do no live long, are mainly nocturnal and only flash their colours when excited or threatened. So we don't really reccomend trying to keep them.

Octos do best without tankmates, small fish get eaten, fish equal to or larger in size will also be taken on (Giant pacific octos sometimes eat sharks). If the fish is much larger than the octo, say goodbye to your cephalopodian friend.

Sorry to be so negative but I hope this helps.
Man that is a bummer... what kind of octo do you reccomend? i really want a tank with one but i want to be able to enjoy other animals also... Does anyone have a setup with and octo plus other inhabitants?
Hi Ryan, its a common question and the aswer is an definite no to keeping cephalopods with anything other than a starfish or urchin!

Many people have tried and as Joel points out, ends in dissaster! So really an octopus tank is a species only tank.

Where do you live? this has a great influence on what's available to you.
Definitely a Bimac, they're active in the day, interact well, show pretty nice colours and are captive bred by www.octopets.com . I thought lions would be fine with cephs but about a month or two, or maybe even three ago, my cuttle ate a lionfish the same size as it. Eels unfortunately are natural predtors of octopus. Stuff that you could put with octos are echinoderms like starfish ,urchins and maybe a few other stuff.
I live in Seattle, WA..... so frusterating =)

Ok say i get an octo and a same size lion... i think i'll take the risk.. what other fish can i get? Also how many lbs of live rock would you reccomend for a 120 gal?
RyanK said:
Ok say i get an octo and a same size lion... i think i'll take the risk.. what other fish can i get?

think your missing the point a wee bit :smile:

If you put a lion and octo together it wont end well, and its not really YOU that's taking the risk!!! i'd say the octo and lion were. So to emphasise the point...

mixing any fish, crustaceans or other cephalopods with octopuses is NOT a good idea
The problem is if even if you get the largest lions, say a volitans which grows to 30cm, the bimac would be able to take it on anyday. Heres some evidence of my bad encounter.
Good Heavens! That pic looked like an HR Giger painting! :shock:
Octos are so much fun to keep, that you really don't need any fish in the tank to be admired...once you keep a ceph, fish will pale in comparison!
Pardon the pun, of course!
Octos are probably the best thing to keep in a sw fishtank. I did have an octo who was kept with 2 damselfish but they're boring as hell and was at the LFS with about 6-8 seahorses that he "rode" by grabbing their necks and it looked like he was trying to get the jugular. He only killed 1 in the end, that was by inking when the LFS owner was taking him out.
Greg's right, almost all fish (except for seahorses) suck in comparison to octos.
It depends on the octo what it considers as "food" my cuttle for example refuses live crabs but eats live crayfish, sometimes the octo goes for the seahorses, other times they leave the horses alone. My pygmy octo didn't bother my seahorses, but then again the seahorses were much larger than it.

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