Octopus cost


Apr 19, 2010
So I've figured out that the probable best options I have if I ever decide to get an octopus, which I am entertaining at the moment, are probably O. mercatoris or O. joubini. They are tiny and would probably not take up a ridiculous amount of space.

If one of you owns one of these species, can you give me a reasonably itemized list of expenses, as well as how often you have to make these purchases?

I want to know how much money I'd have to spend on this thing.


Certified Ceph Head For Life
Staff member
Sep 4, 2006
Gainesville, GA
Without some knowledge of your saltwater keeping experience, it is difficult to respond. Saltwater environments don't come cheaply so I am not sure at what point in the process you are trying to itemize. If you are asking about recurring expenses for just the merc (outside the routine marine environment maintenance) basic food considerations are somewhat varied on the specific animal and what it will accept. If the animal will take dead food (most will over time) then feeding becomes less expensive. Most of mine would not accept raw table shrimp but my current female takes it readily. All will take live fiddler crabs (every other or every 3rd day recommended) and you can reliably source them from Paul Sachs if you don't have a local supplier. All of mine would also take freshly killed (which means purchasing and keeping live) shore shrimp (also available from Paul). Some people have had good luck feeding live hermits (I have not had success with them). It is important to vary their diet so at least two foods but more are a good choice.

If you have never kept a marine environment then there are start-up and maintenance costs that get pricey even for a small tank. You will need a source (home made or purchased) for fresh RO/DI (if you are purchasing water distilled is an acceptable - sometimes better - alternate). You will need to make or purchase RO/DI saltwater for weekly water exchange (the fresh is for topping off evaporation).

The tank will need some kind of skimmer and filter (I use a Skelter hang on for both) as well as a quantity of live rock for both filtration and denning. I add a set of giant purple barnacles to all my merc tanks (in addition, not in lieu of) to the LR to entice viewable denning. I prefer a minimal bottom substrate (1/2" - 1" of argonite sand to help buffer the water). Mercs are nocturnal so rigging a decent red light (I leave mine on 24/7) is highly recommended.

If you are totally new to saltwater, here is a recent thread that discusses items needed to get started

Ryan Smith

Feb 16, 2010
Well you are in for a rough few weeks/months in my case rounding up funds to start your tank. For a small tank, 20 gallons or so will cost $500 or so (I would estimate). My 40 gal setup should run me $800 or so, and for a larger tank more. I did the approx calculations and Im thinking $50 per month including food. But it depends on A. tank size B. if you buy or make your own water C. appliance sizes (tank size) the bigger the filter the more expensive the cartridges. D FOOD! can be one of the most variable expenses. It depends on if you are feeding it frozen shrimp, live shrimp, crabs, etc. And how big your octos appetite is.

Members online

Forum statistics

Latest member

Monty Awards

TONMOCON IV (2011): Terri
TONMOCON V (2013): Jean
TONMOCON VI (2015): Taollan
TONMOCON VII (2018): ekocak

About the Monty Awards