I need help with tank design


I am currently setting up a 29 gallon tank for an undetermined ceph, and want some advice as to what type of filtration system I should set up. As we all know, water quality is of the highest priority and having a closed top somewhat limits options. I really don't want to drill my tank, so what route should I take? Out of curiosity, what do you guys use to secure tops/canopies? Any help is greatly appreciated.

The one I setup for an Octopus is a 75g and was drilled in the back wall so that everything could be put in a sump, out of the way. I didn't know how to seal the tank with all the equipment and cords and such so I did it that way.

I sealed the tank with a sheet of clear cut acrylic, with two holes cut for the return pipes from the sump and the cords to two powerheads. The acrylic was sealed with old faithful - masking tape. Certain species like Bimaculoides (pacific) apparently are not too prone to attempt escape.

In college (10 years ago) I had an octopus in a 30g with a perfecto hood, again sealed by masking tape. That octopus lived for a several months and never tried to escape. the tank even had a old undergravel filter with an aquaclear hanging off the back. I cannot remember how I sealed the area around the aquaclear, but I bet that it was with masking tape. That octopus died when I moved him to another tank for a college break, so I am not sure that filtration by an aquaclear and undergravel filter was inherently wrong.

I setup a small tank for an octopus as well recently. Read the last thread in this forum and you'll see that rinaldi and I both haven't had any luck with cephs lately =( Our tanks are setup in completely different methods, but neither worked. On rinaldi's behalf I think he just had a sick octopus from the start.

I have a non-drilled 10g that I'm using. I cut out a piece of acryllic and drilled two holes in it to fit a canister filter. I also drilled a small hole for a heater cord and now a small hole for an airline (goes to an airstone).

You can secure the lid with ductape or silicone. Either should work ok, but make sure you have a weight on the top just in case.

I talked to the owner of fishsupply.com (where we got our octopuses) and he said we pretty much had things right... temp of 72-76 degrees... lower lighting... mechanical filtration. The only thing he said I may have done wrong was that I took 4hrs to acclimate my ceph. He said to keep it between 1hr and 1.5 hrs.

Also before you buy your octopus, make sure you have a food source for it. This would either be 3 hermit crabs (medium size) per day, live shrimp, live SALTWATER crabs. Your ceph will arrive hungry most likely and freshwater foods are a no-no. The only thing I can get around here are hermit crabs and ghost shrimp.

Good luck and keep us posted!

Thanks for the input guys. I think I'm going to go for a one piece plexi lid with a couple small holes for cords. I hope I have better luck than you guys have had lately. Time will tell...

thanks again,
Glad to see people out here have interests in cephalopods.
It's always a good idea to button your tank up, but believe it or not I don't on any of my tanks. Depending on the species you acquire you may need too how ever. There has been recent discussions in the ceph area what species are prone to "escape" and those that don't. Conditions of the water and tank set up "do I have a place to hide?" is also a point of stress that can cause escape.
Certain species are known to escape and will try most of the time and other seem to have no interest in leaving their home. O.vulgaris,O. briarieus,O. joubini are species that will leave the tank given the chance. Other species like O.bimaculatus, O. bimaculoides seem to have no urge in leaving there home. I had a rare O. macropus species that hated to have even the slightest bit of arm out of the water and would only come to the top of the tank to feed.
Most people have no idea what species there getting when they order off the web or in the pet store. There are not may people that can identify species unless they have studied them for years. I have orderd a bimac off the web and received a rare macropus. A friend ordered a O.vulgaris from the Atlantic and received a bimac, a ceph from the pacific. You just never know some times.
Some recommend using a all mesh top made out of fiberglass window screen to allow the tank to breath, and swear by it for keeping octos in. I my self have not had escape so far, but I know what species I have and what there prone to do. A friend has almost a dozen cephs and has not had a escape as well. Most of the cephs were bimacs. Until you feel comfortable you can recognize what you have its a good idea to keep the lid on things, no matter how you do it.
My friend Jack at fishsupply.com is your best bet for a bimac, he knows how to identify a bimac and will send you a nice one. Make sure you tell him you want a bimaculatus. Just tell him the octopus guy sent you.