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Substrate question for all you ceph keepers


Staff member
Moderator (Staff)
Nov 20, 2002
Dallas Texas
Hi everyone,
I've been curious what kind of substate you have. Please tell us

-what kind of substrate (fine sand, coarse sand, gravel, etc.)?
-if sand, is it aragonite sand?
-did you use live sand in setting up your tank?
-how deep is your sandbed?

Do you have shells, marbles or anything else in addition to live rock?

Let me start:

I have a fine sand substrate.

Later I replaced some of this with a similar aragonite sand.

I used dry sand when the tank was set up - any later replacements were live aragonite sand.

My sandbed is 1" - 1 1/2" deep.

I have small shells and may add some larger ones.

I'll go next:

I have fine sand.

It's live aragonite sand.

It has small shells that were mixed in with the sand in the bag, and a few larger ones that were also mixed.

I always had turbo snail shells with my bimac, Blinky, for her to use as a door.

I did have marbles, but she never showed any interest, so I removed them.

My current ceph tank sand is 1" - 1 1/2".

I have fine sand (but not sugar-sized). It was not live when I purchased it I just let the LR seed it. Sand bed is 1-1.5 inches. I keep anything that falls off the rock in the sand (small muscles, hitchhiker snails, etc.). I also keep all dead snail shells in the tank too. I don't like things that look unnatural, so I don't have any marbles, colored stones, etc. I believe the sand is aragonite.
did anyone find a difference at all in comparing live sand to just normal 'dead' sand?
I have a mixture of fine sand and semi-course sand.

I used live sand to start the tank.

My sandbed is 3-4" deep.

I used to have alot of shells but removed them as I felt they were contributing to poor water quality (I seemed to be right). I do have some small shells but more scattered pieces of live rock rubble. I have alot of gorgonians and leather corals in the tank as well. My live rock is very pourous and my current Octo is able to have three different entrances to a den inside one piece of live rock.
Colin;105872 said:
did anyone find a difference at all in comparing live sand to just normal 'dead' sand?

None at all - except for price. :biggrin2:

In the main system I have aragonite. It two of the smaller tanks I have carib sea mineral mud. The cuttles seem to like the mineral mud more than the sand. In the baby tank I have very fine aragonite right now.
I use fine aragonite. I am thnking of adding black sand or mineral mud in my juvenile cuttle grow out tank. Right now that also has fine aragonite and babies are mainly white.

I use sand from my previous setup, so it is 'live'. The bagged live sand does not have any real benefits over normal sand.
I do not add shells or marbles, but then again, I keep cuttles not Octos. I also like to keep it looking like real reef setting.

My sand bed is 2-3 inches.
Hijack alert! There is often sand near corals in a real reef setting. I think the idea of a natural looking tank with sand isn't that it actually looks more natural, rather it is what we have come to expect to see at the bottom of aquariums. :biggrin2:
yeah, i think it looks nicer too :smile:

My own personal preference is actually, play sand mixed with coral gravel and some larger bits of gravel through it so that it isnt all one grade. The aragonite is really just to buffer the water. My current marine tank is just 100% coral sand of about sugar grade and its a bit too bland for my liking.

I very rarely have the depth over 1 - 2cm though as its easier to clean. I have also found that cuttles seem happier to bury themselves in playsand rather than aragonite... easier maybe?
In fact, you can kinda make out the differnt sized substrate in the cuttle avatar i use :smile:
For our big octopus we have artificial rock over most of the tank with a "playpool" of native silica sand mainly for the benefit of the crabs as P. cordiformis doesn't burrow as a rule. In the small octopus tank (O. warringa/huttoni we have a deep sand bed (around 30-40cm) of fine to medium grained silica sand. In both cases there are loose rocks for them to aquascape, shells etc

shipposhack;105890 said:
Is your small tank not filtered with fresh seawater? Do you think the DSB helps with NO3 and PO4 reduction?

All our tanks are flow through seawater. So NO3 and PO4 are not an issue (I LOVE being able to say that :biggrin2: ). The DSB is for the octis to burrow in so they don't disturb the undergravel filters (otherwise they live under them :roll: ) Also it lifts the display up to make it easier for visitors to see the critters.

In my 40 gallon, I use a small but not fine coral sand (not purchased live - I will never do sugar fine again - have some in a reef tank, cloggs up everything and bothers some of the corals when it gets disrupted during cleaning). The front of the tank has 1-1.5 inches wide of 6 inch depth sand the rest of the bottom is only about 1-1.5 inches deep and covers a DYI resembelence of a UG. The under gravel plate is not for filtration but houses a filterbag covered intake for the powerhead. Normally, my nitrate is tollerable but with the babies (and the feeding density), I am struggling to keep it down. HideNSeek used to bury, or at least dig under the LR and sleep in the sand bed without skin issues.

Sisty and Medusa's smaller, 15 gallon tank has the same sand but only about an inch deep. Nitrates are never a problem but they do get a higher percentage water change since there is no sump. Neither of them dig but again, no skin problems.

Two of my non-ceph tanks have a large, almost pebble substrate that collects everything, is hard to clean, propetuates nitrate and grows algae, another substrate I will never use again.

My 4' tall x 1' diameter has golf ball to fist size LR loosely piled on the tank floor. The tank empties from the bottom and has a water movement pump low in the tank since the substrate can't be cleaned. This works well but my other half won't let me try it in a more normal tank for esthetic reasons :hmm:

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