Can I Octo Proof this overflow?


Jul 27, 2016
I just got this set up a few days ago, and I'm cycling it as we speak. However, can this setup even be octo-proofed? Or do I need a whole other set-up? I'm wanting to get a Octopus briareus this october.

Any help would be greatly appreciated!



Staff member
May 30, 2000
hmm... I think everything is octo-proofable, but some are more difficult than others... and you definitely don't want to cut any corners, they will find a way! :goofysca:

Hopefully one of our resident experts will weigh in. What are your tank dimensions?
Sep 16, 2005
Can you take an overall view of the top of the tank. Kind of hard to envision what the whole area looks like. Are you hoping to put an acrylic lid over everything or is there already some sort of top?
Aug 13, 2009
The first problem I see with this is the fact that you are using an HOB overflow box and not a "more traditional" drilled overflow. The problem with these guys is they can be very finicky when it comes to starting, stopping, and starting up again. IMO the best way to block up and overflow is by squeezing a coarse sponge into the overflow that is slightly large than the space it is going into. That will provide some resistance against an overly determined octopus. The problem with that is that it would restrict the flow going into the HOB overflow and you may have issues matching the flow rates of the drain and the return. This problem would also arise if the sponge ever got dirty or clogged, in which the box would slow or stop draining, and you'd flood the tank and drain the sump. If the octopus you have or want is too large to fit through the teeth of that overflow I would just cut out an acrylic sheet that fits the entire length of the tank. You'll have to cut wholes the exact size and place of the U-pipes in the overflow, and the return pipes, but that would keep from having flow issues. You'll also need to raise the overflow box up to acrylic lid or put a sponge between the lid and overflow box to keep the octopus from climbing up and over. I see in the pictures you have it almost as low as the thumb screw can be. Just my two cents. Take it with a grain of salt and wait for more people to chime in.