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Bare Bottom?


Sep 2, 2006
I'm thinking of pulling my 2 in sand bed from my ceph tank (no octo yet - want to make sure all is PERFECT first!) I've heard that unless you have at least 4-5 in that it really doesn't do any good anyway in the way of good bacteria - True or not?
A bare bottom may not be quite as esthetically pleasing, but MUCH easier to keep detritus off. Beside it will be covered with coralline in no time. If I pull the sand now (my tank has already cycled and been running for about 4 mo now) will throw the balance out of whack?
Will an octo be okay without substrate? I will still have 80lbs of live rock of course.
Thanks for any input!


Staff member
Sep 4, 2006
I've have grown more and more fond of minimal bottom substrate but have not gone to bare bottom (yet). I believe Thales does this with his cuttle tanks but I can't think of anyone trying it with an octopus. Some octos like to dig and some of them bury, they all walk a lot (vs swimming) so the bare bottom may not be desirable. It is my understanding that for bottom substrate (LR is actually also considered substrate) to be effective, you need a minimum of 6" of undisturbed sand and so a separate filtration tank would be the most beneficial. The DSB builds up toxins that "eat" nitrate but if freed to the tank, creates a poisonous environment. Keeping the sand thin enough to stir and vacuum seems to be the going advice, however, I have a mixed group of setups that, once mature, all seem to work reasonably well.

Removing the sand will most likely cause a slight disruption (depending upon what is in the sand) but the tank should recover quickly and without an octopus already in residence, you should not have a problem if you decide to try it or chose to minimize the depth.
Sep 8, 2006
Something to consider is that the octopus won't be able to "walk" on the bottom if it's just glass. I've found that certain things do effect the different behaviors you will observe from an octopus. Like space and texture. There isn't enough room for my briareus to "walk" around in the tank so I've never seen it do this behavior. The abdopus' tank however I specifically made a sandy open area for it and it does some interesting stuff I'm pretty sure I wouldn't have otherwise seen. It doesn't use the same mode of transportation on the rocks or glass at all. Another thing just to add to this, is the swimming room available. Kalypso (briareus) is just way too big to actually swim in the tank. The Abdopus however is a smaller octo in a relatively larger tank and swims a lot.

I guess what I'm saying is, offer a wide variety of textures and spaces and you'll get more out of your octo. I personally think the climbing around on the glass is the least entertaining/interesting activity.

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