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Escape proof tanks

Neogonodactylus

Haliphron Atlanticus
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Mar 17, 2003
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The cheapest and easiest method to create an escape proof octopus tank that I have found involves replacing the canopy on a standard 10, 20 or 35 gal tank and cutting a sheet of glass (at least 1/8th inch thick) to just fit into the depression around the top. You have to measure this carefully and have the glass cut to precise specifications so that there are no gaps when it is in place. Glue handles or use suction cups to help in lifting the glass for maintenance. Do not use plexiglass. It will warp and leave gaps through which the animal can escape. Large octopus may be strong enough to lift the lid, so I always place a heavy weight on top of the glass. We also use a lot of custom built all glass tanks for photography. With these I just make sure that the top edge of the tank is even all the way around so that a piece of glass placed on top forms a good seal with no gaps.

To provide access for circulation and filtration, I use a diamond drill to cut two holes about 2 inches from the top of the tank. The location of the holes will depend on where you want the water inflow and outflow tubing to be located. For a 20 gal, I use a 5/8th inch drill which allows me to pass 5/8th inch tubing through the holes and connect a canister filter to the tank. The simplest and easiest connection is to use a 3 inch length of tubing in the hole and force barbed elbows into the two ends of the tubing. This will stretch the diameter of the tubing so that it forms a tight seal. A more secure approach is to plumb through the openings with pvc bulkhead fittings or use threaded male and female connectors. This will require drilling a larger hole. Attach the canister inflow to a fine strainer in the tank (I also cover it with a foam block.) and the outflow to a spray bar with very small holes.

I've kept hundreds of octopus ranging from blue-rings and various pygmy species to bimacs and Pacific Day octopus in these types of tanks and have yet had one escape through the holes for the tubing although occasionally we forget the replace the weight on the glass top and strong octopuses have pushed up the glass and escaped. For robust animals like bimacs or Larger Pacific Striped Octopus, latches added to the top of the tank provide added security.

Roy
 
One interesting thing we think we have discovered (or at least we have never had an escape with a limited set of species) is to put a (roughtly) 2 inch surround around the top of the tank and then affix the lid to the surround. For whatever reason forcing the octo to reach around the 90 degree turn created at the edge seems to eliminate escapes. We DO lower the water lever about 2" from the top of the surround so that not only does the octo have to navigate the 90 degrees, the surface is above the water. So far, even with an occasional lid accidentally left open for a few minutes, we have not had an escape for any of the Caribbeans or the one Bimac housed this way.
 
Generally I think this works, but there are a few species that will defeat the surround. LPSO's will reach up out of the water and brachiate arm over arm all the way across the the top of the tank.

Roy
 
Interesting little monkeys you two are observing! I am hoping to see both at TONMOcon V.

I can picture it well and remember one of my mercs housed in a small tank doing something similar. The surround in that tank was quite deep and he never found/explored the center opening. Of the animals I have kept, he was the only one that would come out of the water like that and he almost appeared to shake supporting his weight. Does its larger cousin appear as rambunctious or does their larger size add enough weight to prevent this type of travel?
 
It would be nice to be able to generalize about what species will leave the water, but I don't think we can. I used to think that species that lived subtidally were more prone to escape, possibly because they had no experience with air - water interfaces, but that now seems too simple. There certainly are many intertidal species that will leave the water, probably because of the need to escape tidepools (and a few to hunt).

Roy
 
DWhatley said:
One interesting thing we think we have discovered (or at least we have never had an escape with a limited set of species) is to put a (roughtly) 2 inch surround around the top of the tank and then affix the lid to the surround. For whatever reason forcing the octo to reach around the 90 degree turn created at the edge seems to eliminate escapes. We DO lower the water lever about 2" from the top of the surround so that not only does the octo have to navigate the 90 degrees, the surface is above the water. So far, even with an occasional lid accidentally left open for a few minutes, we have not had an escape for any of the Caribbeans or the one Bimac housed this way.
This is a great idea, Duct tape works too/with a waited top lol, jk...
 
DWhatley said:
One interesting thing we think we have discovered (or at least we have never had an escape with a limited set of species) is to put a (roughtly) 2 inch surround around the top of the tank and then affix the lid to the surround. For whatever reason forcing the octo to reach around the 90 degree turn created at the edge seems to eliminate escapes. We DO lower the water lever about 2" from the top of the surround so that not only does the octo have to navigate the 90 degrees, the surface is above the water. So far, even with an occasional lid accidentally left open for a few minutes, we have not had an escape for any of the Caribbeans or the one Bimac housed this way.
We do have duct tape/velcro + weight designs that have worked well but over time they get messy and the tape/velcro needs to be replaced. For long term tanks, I suggest designing a permanent lid securing structure.
 
Sometimes you wish you never mention success with a less safe approach. We lost our O. burryi tonight because she escaped the tank. She has been known to upset the water flow in this tank so that the water will rise and to a point of overflow (not at the actual top but through an oddity of the tank about an inch below the top in a connected sump type area). Whether she did this and then reached the lid or simply climbed out of the water and forced the unlatched lid open we will never know but she crossed the room and went down half a flight of stairs before she died. ... "it works until it doesn't" is always a painful lesson.
 
I just wanted to add in the solution I've been using.

I had heard of Velcro which seemed like a good option until I heard of it getting nasty from being exposed to water.

Instead, I found a product called DualLock (also sold under other names). It is 100% acrylic and 4x stronger than Velcro.

3281_xl.jpg


I superglued one piece to my center brace where the lid closes, and used a 2 part marine epoxy to attach the other part to the glass lid.

It works perfectly now. It's a very strong bond, and completely waterproof. I like it since it doesn't affect how the tank looks externally.
 
IMG_5513.JPG
I am new to owning an octopus and in the process of setting up my first tank to house my new pet. I bought a Red Sea Reefer 250 aquarium (55gallon) with a built in skimmer and pumps that all operate through a downflow system. The top edge of the tank is glass with no need to run pipes, hoses or wires through the top. My question is, if I affix a piece of acrylic (like plexiglass, although thick enough and not prone to warp) should I drill holes for air, if so how much? Roughly what size is the max size of an air hole I should consider without knowing the exact species (I've read the section on what the local fish supplier will know about the species, and yes, it's a "common octopus" "probably from Bali". This tank top that I'm considering will sit flush against the top of the tank with weights around each corner to prevent a strong octopus from lifting the top, please advise if you don't mind. I'll post a picture of the tank as it sits right now without the top
Thanks
Scott
 
Scott,
We opt to drill holes in our lids (Here is one that we drilled). We used a peg board as a template and a sharpie on the plastic film liner (that peels away) then drilled all the holes where the marks indicated. I suggest sizing the holes so that a bamboo skewer will snugly slide through (for occasional cleaning). Keep in mind that the water side will be cooler than the top so you will get some warping even with very thick acrylic. Keeping weights on at least the 4 corners at all times will go a long way to minimize the warping.
 
Ok perfect. My other thought was to use a hardwood frame and screen (same principle as a screen door). I'm just unsure of how much oxygen flow is needed, I can for sure see this lid sweating and warping so maybe the screen door type lid would be better? If I do this I will make sure the edge of the tank sits inside the frame so there will be contact with the frame on the entire top edge of the tank as well as the sides. If you recommend this way I will scrap the acrylic lid and make something like this. Thanks for your help and I'll be sure to post a pic of the lid once I'm finished
 
I definitely like the acrylic and use it on all my tanks but I wanted to warn you about how and why it warps. I have experimented a little with fiberglass screen and am not fond of the ease the aluminum frame twists so have not used it on a tank.
 

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