• 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.

Reef Safe?


Feb 5, 2006
I've been reading up lately on cephalopods and I am checking between maybe a cuttlefish (bandensis) and an octopus (bimac), but from what I am hearing, octopus bimac. aren't reef safe. Why is this? Is it the lights? Flow? Has anybody kept a bimac in a reef? Will a 250 watt MH blind it? Thanks for the help. I tried to use the search function but didn't see many results on the topic.

the main reason is that bimacs, get relativly large, they produce lots of waste, they eat all other vertebrates and most invertibrates, and have the tendency to nock over corals
Hi Mark, there are a few other reasons they are not too reef safe. They require a lid (at least the octopuses do) that blocks your halide lighting, has to be cleaned etc. Also most reef tanks have auxillary flow in the way of pumps and powerheads. All openings must be covered to prevent the animal from checking it out and becoming injured. Also they eat alot of meat and so excrete alot of nitrogen based waste - not great for a reef tank.
The term "Reef Safe" is banded around a lot and it's general meaning is sometimes nisunderstood.

I've seen people complain that their "Reef Safe" lobster killed their fish, it's a predator... it eats fish. That does not make it any more or less reef safe.

The way I understand it is that reef safe means that it will not harm a reef tank, but meaning reef as in the invert. sense. While an Octo won't eat corals which some butterflyfish/puffers might they can damage them by climbing all over them and they can too also be stung by some corals of, for example the genus Euphylia.

Also beware that bimacs love eating bivalves such as clams... and if you have a good £50+ maxima the last thing you would want to do is to add an octo and watch it get munched.

Totally agree with everything people have said above though, just thought i'd add my ten pence

I'd also think that a 250 watt MH would be too much for an octo. You might find that they will just and you'd probably not see much from them. You would however need that lighting if you wanted to keep SPS corals!


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.