Hello :)


Larval Mass
Hey TONMO! I just found this community and I am absolutely infatuated with cephalopods. I would love to own one in a tank I am currently looking to invest in. I was going to wait and do some research about tanks before purchasing and now that I have found such wealth of knowledge about keeping them in tanks I wanted to ask what an ideal set up would be to keep an octopus. Do not filter the ideas because of money, please post what all I would need. I have never had an aquarium of any kind. I would really like advice before taking on this monumental challenge :)


Colossal Squid
Staff member


Colossal Squid
Staff member
:welcome: to TONMO. I'd suggest you start with the articles link at the top of the home page (here's a short cut: http://www.tonmo.com/forums/content.php?119-Ceph-Care-Articles ) to see some of the distilled wisdom on the keeping of cephs... Also, Nancy and Colin have a book that's advertised on the main page, which covers ceph keeping in great detail.


Well first read all the care articles and threads that you may have questions on. Research
research research! Octopus water quality needs to pristine, so salinity 1.026, pH 8.2, 0 ammonia, nitrate, nitrite. ZERO COPPER!!!!!! ANY amount of copper will kill an octo. The temp for tropical octos (the most readily available) is 78ºF. Don't get a tank smaller than a 55gal. Some octos (like Briarius) need tanks around 90-120gal. Plan which type of octo you want to get first. Live rock and sand are very important. The filter should be a canister or wet/dry filter. An outsized protein skimmer is veeeery important. Only use RO/DI water, I would recommend buying a filter. No stinking corals should be in the tank and lights shouldn't be too intense (I'd say don't go higher than power compacts if you want some coral).
Its also important to have a secure tank with NO escape wholes whatsoever since octos can escape through any hole they can fit their beaks into. Net all intake tubes.

This is a great site, good luck!


Staff member
Allow for a at least a year of learning how to maintain a saltwater environment. Go slowly. The hobby is not a science and the science is just trying to look at the iceberg. You need to come to a good understanding of the environment first then build on that knowledge. We have several members that have successfully started with cephs but they spent a lot of time learning before finally adding an octopus.

Since you think you want an octopus, keep in mind the tank size. Starting with a nano is a good idea but it will not support most cephs (there is one exception but the animal is not exciting or very interactive but some people:wink: enjoy keeping this shy little octopus) . If you have an interest in corals, the nano can give you a place to put interesting things that should not be placed in a ceph tank. It can also become a tank for feeder animals or a number of other interesting things, including a refugium or sump for the future ceph tank. For an octopus tank plan on something of at least 55 gallons and preferably with a 20+ gallon sump (look up and learn the uses and configurations for the italisized words).

You will need to understand the nitrogen cycle and the mechanical and biologic combinations we use to emulate an environment for ocean animals in a confined area. You will need to lean more than the simple chemical concept to understand how it applies to the aquiarium and how to recognize avoid mini-cycles through tank maintance and observation. Successful marine aquariums require consistent maintenance. Accepting that you will need to dedicate part of one day a week to the caring for your tank (or participating in your hobby, depending upon how you look at it) is something that is hard to learn if you have never had a demanding hobby. Although we throw a lot of mony into these glass boxes, there are few alternatives to the time required to keep them going.

You will need to lean to keep the water environment stable and consistent with the addition of freshwater (usually a daily necessity) and water changes to take out some of the pollution and refresh with new saltwater (usually a weekly or bi-weekly requirement). Additionally, you will need to think about how to obtain the purified water for both freshwater top-offs and saltwater maintenance.

I DO encourage you to read the tank forum for special requirements for an octopus tank but much of it will be difficult to understand until you have some of the saltwater basics under your belt.

There are tho very old achronyms and an expression I often quote about the hobby that you will find relevant as you learn.

NTS or New Tank Syndrome describes the effect of thinking you have a cycled tank because you see no Ammonia or Nitrites (and often told by your aquarium store that you can begin stocking). Most everything put into the tank dies within a month.

Nothing GOOD happens quickly in a saltwater environment.

MTS or MultiTank Syndrome occurs when you finally learn that not all animals can be kept together successfully. The affliction is common and many of us have it (myself included).


MTS or MultiTank Syndrome occurs when you finally learn that not all animals can be kept together successfully. The affliction is common and many of us have it (myself included).
Had this discussion recently. I wanted to feed my sps tank rotifers, and feed the rotifers live phyto plankton. (2 more tanks) Then I wanted to switch to feeding cuttlefish primarily live foods. Pot-luck at the coast brings home: Crabs, Amphipods (kept together), Mysid shrimp, mummichog. (3 more tanks). Want to start a tigger pod culture for baby cuttle first food (1 more tank). Might have to go with live small mysids for 2 - 3 weeks (1 more tank) and feed them bbs (yet another set-up). Did I mention I would like to try keeping a separate copepod culture?

Find someone you can trust, in a local reef / sw fish club. Great deals on used equipment abound. I have had success "short cycling" a set up, by filling system with at least 1/4 to 1/3 water from someones long established tank. Adding a cup or 2 of well established substrate to yours will help as well, and using well cured / established live rock. IMO, dry rock is nearly worthless for at least a year or so, and even then I believe it to be a weak bio filter medium at best.
Just my humble opinion though. There is more than one way to start a sw tank. The above suggestions have worked very well for me.
This tank has only been running about 6 mos. but stocked with mostly cured / cycled rock, water, sand (sump sand). No excess nutrient or cycling issues were had. Not that I would recommend a newbie trying this, but to show that it can be done.



Larval Mass
CaptFish;157755 said:
:welcome: to TONMO

A great place to start is with this book. It was written my two TONMO staff members its a wealth of information.

I have already ordered the book, now I am just going to try and figure our what species of octo I would like. I will be reading the care forums and all in this website however I was wondering if there were any parts of a tank that exceeded expectation with octos in the tank, also can any other life form be kept in the tank w/o the octo either eating it or destroying it? Thanks :)

Members online

No members online now.