• 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.

New Briareus!

Jun 3, 2007
So I won a baby briareus on Ebay and received him in the mail a couple days ago! He's about the size of a 50 cent piece. I named him Octavius. :biggrin2: He's in a 50 gallon with a Seaclone 100 Protein Skimmer, a Fluval 304 filter, and a small heater to keep the temp a little bit above room temperature. I have mostly reef rocks in there - no live rock yet. For the substrate I have a layer of crushed coral with some live aragonite sand above that.

I'm really happy that I fed him a small square of frozen shrimp. He accepted it after me waving it around him on the feeding stick for about 30 seconds. :] Have some fiddler crabs from that aquaculture store on the way too! Just hope they aren't too big for him to tackle.

I have a few questions for you experienced ceph keeprs:

1) Is it reasonable to assume that a baby octopus would produce less waste than an adult and therefore the ammonia levels would stay fairly low? I've read a bunch of posts on here saying like "three months minimum before you even consider putting anything in!" but found an interesting post that said "if you test daily and do water changes very frequently, the cycle will take longer but you can put stuff in right away." Prior to putting the octopus in, I had a fair amount of fish in there for about 2 weeks. I removed them all before I added the octopus and did a water change. He seems to be fine as he accepted the food on the second night in the new environment!

2) Is there anyway to make him feel braver so that he won't hide all the time? I've been trying to keep the lights dim and I use a red LED light to look for him but I guess it's just a waiting game.. can't wait to see the colors flash!! :]

I'm well aware that octopuses are very sensitive but I think this one will do just fine in the setup that he's in, if I'm careful, correct? I have no school and just a part time job for the next 3 months so this shouldn't be too much of a problem!

Anyway, I love this site. Go octos :] I'll post some pics for sure once he is more comfortable!
:welcome: to your new octopus.

There should be no ammonia readings in a seasoned tank. If I am reading your post right? This is a 2 week old tank?

Best thing for your new octopus is to let him come out on his own. Sometimes it can take them up to 2 weeks but in the long run if you allow them to get used to their new surroundings on their own, they become so much more friendly.

Good luck.
Krakilin;96401 said:
I've read a bunch of posts on here saying like "three months minimum before you even consider putting anything in!" but found an interesting post that said "if you test daily and do water changes very frequently, the cycle will take longer but you can put stuff in right away."

This is pretty much correct, but it isn't a good thing.

Here's a little primer on the nitrogen cycle. I have the day off so I'll write more than you want to know. We'll be talking about three nitrogen compounds called ammonia, nitrite and nitrate. Just about any living thing you can put in your tank excretes ammonia when it pees. Ammonia is toxic: that's why your nose stings when you smell it.

Say you put a fish or an octopus in a new tank. We can expect it to have to pee regularly. If we were to draw a graph of how much ammonia there is in the tank, it would look something like this:


Each day the animal pees a little more and adds more ammonia to the tank. Not shown in the graph is that eventually there is too much ammonia and the animal dies a drawn out, terrible death. Any level of ammonia is very painful for an animal. Remember how your nose stings from the fumes? Think about how low the concentration of ammonia is in the air and its still causing that much pain.

The main reason we put a filter on the tank is to remove ammonia. Basically, we're going to cultivate a population of bacteria that aren't poisoned by ammonia but love it so much they eat it for breakfast.

So if we put an animal in a tank and a filter on it, here's what the ammonia graph might look like:


The animal starts peeing immediately, but it takes a little while for the bacteria to find the filter and start growing on it. Eventually there's a big colony of bacteria and they consume all the ammonia in the tank. The ammonia concentration falls to zero and, more importantly, it stays there forever because as soon as the animal pees, the bacteria consume the ammonia.

This starts to get complicated because the bacteria pee too, so to speak. As they consume ammonia, they excrete a compound called nitrite.


You can see here that when the bacteria start consuming ammonia, the nitrite concentration goes up. The good news is that we don't have ammonia anymore. The bad news is that nitrite is just as bad. Luckily, our filter will take care of that for us too because there's another kind of bacteria that will grow in it that consumes nitrite and turns it into yet a third compound called nitrate.


As you can see, once the second group of bacteria start growing the nitrite levels drop to zero and we get nitrate instead. Nitrate isn't nearly as nasty as ammonia or nitrite and fish can tolerate it in reasonable amounts. The period of time for all this to happen is what's commonly called "the cycle." During this time the water is toxic. Let me show you that graph again, but with another line drawn in:


The blue line is the sum of all three of the nitrogen compounds at any given time. Notice this line looks very similar to the line in the very first graph: the animal is always peeing and waste is always accumulating in the tank at a fixed rate, we're just changing around what form it's in to make it less toxic. It's like going to the bank and getting change--no matter if its in quarters or bills, its still the same amount of money.

I stress this because many people need reminding that their tank is always generating nitrate, and the only technique to remove nitrate for our purposes is to do water changes. 20% every two weeks, starting as soon as the cycle is finished.

Now your tank has been up and running for two weeks with fish in it. Your cycle has already begun, but its hard to know where you are in it without doing water tests. There's a chance that your cycle just finished. If you do a water test and find out how much ammonia, nitrite and nitrate is in your tank you can figure out where you are.

Doing water changes to remove ammonia and nitrite during the cycle is counterproductive because it makes the whole process last a lot longer. You're exchanging a short pulse of high ammonia levels with a long time of low ammonia levels: the tradeoff is a quick death for the animal or a long, slow and painful one.

About the only way to make your cycle go faster is to transplant an existing colony of filter bacteria into the tank. One of the best ways to do this is with live rock. Live rock in and of itself contains a lot of bacteria and is a good filter. If you add a lot of good quality rock to the tank, it might be able to handle the nitrogen load of a small octopus on day one.

So why don't we recommend doing this? More importantly, why do we recommend waiting three months when the cycle will probably be over in three weeks? Because there are a lot of other things going on in a new tank. After the cycle is complete, the water is no longer toxic, but that doesn't mean its a nice place to live. Things like the pH and the alkalinity of the tank need time to find equilibrium and it may be stressful for things living in the tank while those things are in flux.

Good luck,

Thanks alot for the interesting post DHyslop! And yes corw314, it is a two week old tank.

I'm hoping that the slighty overspec filter and skimmer will make it a bit easier for me. I just did a test and the results are:

pH - 8.4
Nitrite - .03 ppm
Nitrate: 20 ppm

Besides that everything else looks good. Argh, I really hate these test strips. They don't feel very accurate.

Off to do a small water change!
I've become a test-strip convert. You're right that they're not very accurate, but you don't need them to be--you really only need to have a positive or negative indication that its in the tank. Your indications suggest that you're near the end of the cycle because there's enough nitrate to register, but there's still quite a bit of nitrite.

If I were you I'd pony up for a bit of live rock if you don't have some already and wait it out.

Shop Amazon

Shop Amazon
Shop Amazon; support TONMO!
Shop Amazon
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.