• 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.

Advice from Local Fish Store and NRCC information


Blue Ring
Dec 13, 2002
I recevied advice from a local fish store concerning a tank setup:
One of the employees said that a bimculoides could be kept in a 20 gallon tank with a Bak-Pak 2 and a Magnum 250 mechanical and chemical filter. Is this setup possible?
In addition, the a setup by a nmember of the NRCC said that undergravel filters can be used, and that a protein skimmer is NOT necessary.

Thank you
Michael O'Shea
I'm told that while undergravels work, there are much better alternatives out there, plus octos tend to love hiding under them...while they need hiding places, under that plate (I gather) is not the most owner-friendly place.

Not sure about the skimmer...I know they're highly recommended for octos. Since skimmers are one of the few things that actually take waste out of the water, I suspect not using one would require (besides better other filtration to compensate) more frequent water changes?

For such a small tank, maybe a "cheapo" skimmer would be adequate?

Also, Protein skimmers put oxygen into the water, something that our little friends need more than other aquatic critters. For the most part so far, I've learned that the one thing you shouldn't cheap out on is a skimmer.
Matt and Rusty are both right,

UG filters can be used but they are very inefficient compared to a 'power filter' and eventually the tank needs broken down to clean it out... There are much better options out there and anyway a UG costs about as much as a half decent power filter anyway once you buy the airpump and plates etc. (octos have been known to climb down the uplift tubes!)


You could also get away with not using a skimmer but they do remove a lot of waste before the filter has to worry about it and they produce water very high in oxygen (100% saturation) and that what we really need for a healthy octo tank.

There are many ways of setting up an octo tank and many people will give many different answers. It really depends on your budget and what you can do, but try to get a good filter and a half decent skimmer, it simply makes our jobs easier and hopefully the cephs healthier.

I think a 20gal is a bit on the small side for a bimac once they are fully grown.... I normally recomend at least 30...


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