• TONMOCON VII Announced | MBL at Woods Hole | Apr 6-8, 2018
  • Thanks for visiting! TONMO is the world's greatest online cephalopod enthusiast community, with interactive content going back to May of 2000, and a biennial conference. If you'd like to join in on the fun, become a TONMO member -- it's easy and free. You can follow us on Facebook and Twitter for more cephy goodness.


Setting up a new octopus tank.

crim

Pygmy Octopus
Registered
Joined
Dec 2, 2008
Messages
10
#1
Hello all. After a few year hiatus from keeping fish, I just put a deposit down on this 72 gallon corner tank that will house a octopus (or maybe a cuttlefish). I've kept saltwater fish for a long time but have never kept cephalopods.

Knowing that I won't have an animal in the tank for 3-4 months, I want to setup the tank with a cephalopod in mind. There is a glass top on the tank that I plan on duct-taping down, and I think I'll use duct tape to cover plumbing holes (unless someone has a better idea). I'd like to keep some simple coral polyps as long as they won't hurt the ceph.

Beyond that, I am just getting ready to put together this setup so any advice is appreciated. Thanks.
 

Attachments

DWhatley

Cthulhu
Staff member
Moderator
Joined
Sep 4, 2006
Messages
19,903
Location
Gainesville, GA
#2
Welcome back to TONMO and marine tanks Crim!

I have found that a coarse sponge (the plastic filter sponge used for filtration is easiest to clean) works well for around plumbing and is easier to form around and in gaps.

Some of the longer buildouts are linked in the Tank Buildouts sticky for ideas.
 

crim

Pygmy Octopus
Registered
Joined
Dec 2, 2008
Messages
10
#3
Thanks for the reply. I will try the filter sponge to cover that area.

Anyone know what type of coral polyps can be kept with octos?
 

DWhatley

Cthulhu
Staff member
Moderator
Joined
Sep 4, 2006
Messages
19,903
Location
Gainesville, GA
#4
I have some brown/orange large "sun polyps" :roll: that have worked well but have had other "brown" that do not. The key if finding softies that have a very low sting and sometimes the only way to tell is to observe and see if the octopus flinches when it touches them.

Octos are not good about going around anything so you need to take this into consideration when placing any stationary animals in the tank. With polyps, I suggest only adding them on their own rock, observing and removing if there is a reaction. Most leathers, mushrooms and gorgonians work well if you can place them with enough lighting and not in a traffic area. Here is a list Dave and I put together that should be helpful (you may also want to read CaptFish's article on why fish are a bad idea if you are entertaining using them to cycle).
 

DWhatley

Cthulhu
Staff member
Moderator
Joined
Sep 4, 2006
Messages
19,903
Location
Gainesville, GA
#6
Sort of a sad picture for me. I now have an empty octo tank an your saint makes me miss our Newfie. Looking good in spite of my melancholy though :grin:
 

crim

Pygmy Octopus
Registered
Joined
Dec 2, 2008
Messages
10
#7
All is progressing. I changed the light bulbs and filled it with live rock. Now I'm just waiting for the water to stabilize before starting to look for the octo.
 

Attachments

DWhatley

Cthulhu
Staff member
Moderator
Joined
Sep 4, 2006
Messages
19,903
Location
Gainesville, GA
#8
It is important to BUILD your bacteria for the next 3 months. Without adding things to decompose your tank will "show" 0 ammonia and 0 nitrite very quickly but it won't have the bacteria needed to convert new ammonia (waste). You can take (hopefully you have acquired your own testing supplies, even if it is just strips) your water to a pet store and it will read, ready to go ... unfortunately, this is true if you bring in newly made saltwater. The key is to force a nitrogen cycle and keep the bacteria growing. For large fish and octopuses, the initial bacteria need to be much higher than for small fish. I recommend not using fish as your ammonia producers but if you do, keep in mind you should remove them before adding your octopus.

If you have fresh live rock, you should see an ammonia spike and witness the initial nitrogen cycle from ammonia->nitrite->nitrate. If your live rock contains very little dead or dying biologic material (often the case) you will have to stimulate even the initial culture. Once you see high ammonia convert, you will want to add critters to feed to keep the cycle progressing. This is the point (often 4-6 weeks) a FOWLR tank would add small fish but I recommend adding hardy clean up crew and feeding heavily. Snails (if you have enough algae to sustain them) and hermits (I like the larger red ones over the small blue leg and they often survive an octo in residence) are a good choice. Feeding them chopped up frozen shrimp will provide more food for you bacteria than most dried. After two months, a hardy serpent star will usually survive. I like to keep these in all my octo tanks and usually have more than one. They can retrieve food bits from tiny places and can often be hand fed (I like the red ones best and the often live in the octos den). At three months you should be ready IF you have continually fed the tank and still see 0 ammonia and 0 nitrite.

Looking forward to vicariously enjoying your new tank!
 

crim

Pygmy Octopus
Registered
Joined
Dec 2, 2008
Messages
10
#10
As far as cycling the tank, I am using the same sand bed from the previous owner so I don't think I'll have the traditional cycle when a tank is started from scratch. When I filled the tank, I found a dead damsel from the previous owner, which I'm not removing. I also have a couple green chromis that I feed generously. I am trying my best to pollute this tank to make sure that it is stable when I add anything.

As an aside, I know that cycling with fish is frowned upon in todays hobby but I've always done it this way. In my opinion, if it's not wrong to use live fish as feeders then I don't think it's terribly wrong to use them to cycle tanks. It's the way I've been doing it for 25 years. I welcome debate on the subject and respect the fact that many people disagree with this.
 

DWhatley

Cthulhu
Staff member
Moderator
Joined
Sep 4, 2006
Messages
19,903
Location
Gainesville, GA
#11
Crim,

It is helpful to know you have a lot of experience and understand the concerns of new tank syndrome so my notes are more for others reading the thread and setting up a tank for the first time.

As far as an octopus tank goes, my concern about cycling with fish is the thinking (we see it often) that the fish can be left as live food. I am a major opponent to keeping fish in an octo tank and removing them is often a major disruption to the tank so I recommend other methods. Damsels of any kind seem to the hardest fish to catch and aggressive when it comes to pestering and picking on an octopus.
 

crim

Pygmy Octopus
Registered
Joined
Dec 2, 2008
Messages
10
#12
Admittedly, I have intended to keep some live food available for the octo, especially in the beginning. While a chromis is technically a damsel, I have never seen them aggressive.

Do you think there would be a problem with trying to keep a supply of hermit crabs and peppermint shrimp for an octo to hunt?
 

TMoct

O. vulgaris
Supporter
Joined
Feb 12, 2013
Messages
98
Location
Colorado
#13
Lots of people keep live food for their octos, and indeed the octopus itself would be strongly in favor of this. The one thing to beware of is keeping them in the same water supply as the octopus itself (like in a sump or refugium), because then your filtration system is burdened with all of the waste from the feeders. A number of people on this forum (including me) get fiddler crabs from Sachs Systems, intermittently and especially with new octopus. I keep mine in about 1/2 inch of mixed saltwater in a "critter keeper" without any filtration, and just periodically pour out and replace the water. Other people have more complex setups.
 

DWhatley

Cthulhu
Staff member
Moderator
Joined
Sep 4, 2006
Messages
19,903
Location
Gainesville, GA
#14
Hummm, I seem to have lost a post. Here is the gist (from another thread) of what I wanted to mention about peppermint shrimp:
I've kept peps from time to time and recommend only keeping two as they tend to gang up on other animals (may not happen successfully with an octopus but they will kill small fish). Usually I see one get eaten and the other surviving. They will definitely investigate an octopus but at least one will learn to stay (mostly) on the other side of the tank. Do put them in the tank well ahead of the octopus as once the octo knows you are delivering food, almost anything you put into the tank while it is watching is considered fair game (may not be eaten but will be investigated as food). Needless to say, do not put expensive shrimp in the tank with an octopus.I've kept peps from time to time and recommend only keeping two as they tend to gang up on other animals (may not happen successfully with an octopus but they will kill small fish). Usually I see one get eaten and the other surviving. They will definitely investigate an octopus but at least one will learn to stay (mostly) on the other side of the tank. Do put them in the tank well ahead of the octopus as once the octo knows you are delivering food, almost anything you put into the tank while it is watching is considered fair game (may not be eaten but will be investigated as food). Needless to say, do not put expensive shrimp in the tank with an octopus.
Even if you find inexpensive peps, the are not likely going to be much in the way of food. If you try to keep them in a small side tank or sump, they may reduce their own numbers (anecdotal observation from trying to keep 3 in a large breeder net. Only 2 survived even when I tried replacing the third).

As TMoct mentions, keeping live fiddlers is relatively painless and minimal effort and Paul is a great supplier. I am surprised you find dead ones in the tank though as they usually survive well even in a deep tank if they have something to crawl on to come up for air occasionally.

I have returned from FL with live "bait" shrimp in an aerated bucket and CaptFish has access to bait shrimp most of the time and has kept several in his tank for regular feeding. If kept separately they need a small well aerated aquarium. Larger shrimp will often be ignored initially but eventually caught and eaten (the ignored part depends on how you introduce them and the individual animal). My granddaughter was quite upset when she learned that the shrimp in the tank was food after one such trip as they are kind of an interesting critter in their own right.

I recently experimented with small pieces of seafood counter salmon (bones fully removed) with success and will try using it again for variety. The person behind the counter kind of rolled his eyes at me when I just wanted a 4 x 2 inch slice but was friendly and accomodating.
 
Last edited:

crim

Pygmy Octopus
Registered
Joined
Dec 2, 2008
Messages
10
#15
All is pretty quiet with the tank right now... I just bought my test kit and tested the water for the first time. Below are the results. Now I'm going to start feeding even more to really put it to the test. So far, all looks pretty good.
 

Attachments

crim

Pygmy Octopus
Registered
Joined
Dec 2, 2008
Messages
10
#16
I realize I haven't updated this thread in awhile. About 10 days ago I got an Indonesian octopus from an online retailer. So far all seems to be going well... The octo is very active at night but has been 100% nocturnal. So far the chromis in the tank is still fine, and most of the hermits seem to be there.

I'll attach a couple pictures I managed to get of this one.
 

Attachments

Members online