• 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.

Crits on planned octo tank setup


Feb 19, 2009
Hi everyone, I'm new :smile: I'm Dante from Canberra, Australia.

I'm also new to aquariums and octopuses. I've been doing lots of research and I'd like to have a cycled tank ready for an octopus by the end of the year.

My first big hurdle has been figuring out an escape-proof tank. My general idea is to have a good-fitting glass lid for the tank and a lock glued to it. Then I'd have a corner weir with mesh that goes all the way up to the lid -> sump -> and a drilled hole with the return pipe from the sump glued into it. That way I can keep all the gear in the sump so the octopus doesn't break it or hurt itself.

I've spoken to my local dealer who makes tanks but he was extremely unenthusiastic and didn't really want to talk about my idea, so I was hoping you guys could let me know if there's any obvious problems with it.

Another quick question I had - just something I'm wondering - does it matter if the sump return pipe is below the water level in the upper tank or not? If it doesn't matter it seems like this would be an easy way to prevent backsiphoning.

TIA! :biggrin2:
Check out (if you have not already) the tank forum as there are lots of ideas about the lids. Heat build up will be something you will need to worry about, especially with a full glass lid. Many of our members use fiberglass screening. I would suggest splitting the lid (perhaps using acrylic instead of glass - this would also allow drilling small holes to let some of the heat escape but would require a center brace) and fastening an acrylic hinge (even if you use glass) to the two pieces. The back section can be stationary but having a hinge makes a world of difference for maintenance (I have also found it to be helpful when an octo tries to escape to have the lid be the direction of the attempt.

An above air retun will add more opportunity for gas exchange (like a cascade filter). No negative effects with that thought and lowering your water level an inch or two from standard would make that easier to accomplish as well as helping with containing the octo. You would loose any benefit from water circulation coming from the return and it might be noisey though. We put our return in a bulkhead at the top of the tank and used standard (black not white) PVC tubing with holes drilled in two row, offset and about 90 degrees apart then added one hole above the water line for siphon break (almost an oversite but the problem showed up quickly when we were water testing).
Thanks heaps for that dwhatley... one question though... do you have problems with circulation in your tank?

I don't want to put powerheads in with the octopus, meaning the only circulation in the main tank is the overflow and the return pipe which would be pretty diffuse if I use a "spray bar" like you've described. Or is circulation not a problem when the sump's aerating the water?
I make use of two koralias in the 60 and in the 35 (that was supposed to be a 45). They are ugly but I swear by them and the black back I insist on along with the coarline algae help hide them) The 60 has the "spray-bar" returns and the 35 a spinning return, both have a SCWD to alter the flow (not sure about the advantages of the SCWD but I stick with it). Over time I have made a lot of changes to the tanks and I am not good at making only one change at a time :oops: so when I get results it is somewhat hard to pinpoint which change contributed the most benefit. I had terrible problems with nitrate until I switched to a thin argonite sand bed and saw an even bigger improvement when adding the koralia's so I stick with that combo. Others will claim circulation is over rated, I would strongly diagree for my tanks.

If this was a science, I would likely have a different hobby :biggrin2:
I am also at the setting up stage of a tank that will be for our local O. bimac. One idea I have been considering is to set my overflow about 15 cm below the lid. It would allow the tank to look like a tide pool; some rocks could be above water level for shore crabs (food). The main thing is it would be nearly (I never say always about an octopus) impossible to escape from the top. The overflow will have to be correctly done. But otherwise it seems like this will greatly simplify a number of issues, hot lights, escape...escape.
Have any of you tried this approach?
About the lid; I used to keep snakes as a kid, and we built our own cages. The designs evolved over the years and got better with every escape. Ultimately I adopted the rule that the top needed to latch automatically upon being closed, and not depend on me remembering to insert a pin, fold down a velcro tab, turn a latch or do anything except let gravity close the lid. I designed my octo tank lid using that principal, so it is both octo-proof and idiot-proof, I can't forget to latch it. I posted pictures on this thread: low outflow to keep octo from escaping from top?

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.