Sand grain size for deep sand bed

[Hondatek]

So I have been reading conflicting info on this subject. Is it better to have sugar fine sand for a dsb. Or is it better to have coarse sand. Also at which point does aragonite sand help with keeping the ph up?

 

[Gti_Leo]

its better to have fine sand. but not to fine that the life in the sand can't move.

this stuff is a good grain size for a DSB
CaribSea® Aragonite Aragamax Oolite - Gravel & Sand - Fish - PetSmart

 

[Hondatek]

Ok that's what I have in my 75gallon. I'm still on the fence about what type I'm using for the 180. That stuff is really fine . I was thinking about the same brand but the bigger grains.

 

[coffeetwitch]

C-RSAND40 Premium Aquatics - C-RSAND40 Aquarium Supplies

hey honda. this is the stuff i was talking about on the pm maybe someone can evaluate it other than me.

i like it . its not sharp. it doesnt compact. i think its fine enough while not being too course.

 

[Hondatek]

yea thats the exact type I was thinking about switching to for the new tank .

 

[Wy Renegade]

Little something I put together a while back on a DSB, might help you with some of your questions.

Set-up:
A properly set-up DSB consists of three distinct layers, each ranging from 1" to 2" or more in depth.

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The Bottom Layer or Plenum: The bottom layer in a DSB can be set up in one of two ways; either a plenum or a layer of very course substrate. This bottom layer is the anaerobic portion of the DSB, and anaerobic bacteria, similar to those found living deep inside the pores of LR, are found here. These anaerobic bacteria complete the nitrogen cycle, by converting nitrates into harmless nitrogen gas. Hydrogen sulfide gas is also produced as a result of this conversion, creating slightly acidic conditions in this area. Generally this deadly hydrogen sulfide gas is broken down within the anaerobic area, however, if this deep layer is disturbed by the hobbiest or deep burrowing fish or invertes, this gas, the acidic water, as well as any trapped nutrients may be released causing the aquarium to "crash."

The Plenum
A plenum is created using an undergravel filter or eggcrate covered with a layer of plastic or fiberglass screen supported above the bare aquarium bottom by inert spacers such as PVC or plastic pipe. The plenum creates an open water space 1" to 2" inches deep.

Plenum for a remote DSB

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Bottom of the Plenum

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Course Substrate
In the event that a plenum is not used (and research has shown that there is no significant benefit to using or not using a plenum with DSBs), the bottom layer can consist of a 1" to 2" layer of course sand, CC gravel or crushed shell; regardless of the substrate used, the material should be course enough that the layer is very porous allowing bacteria to colonize and water to diffuse easily. Using aragonite sand, CC, or crushed shell also allows these substance to break down in the slightly acid conditions of this layer, and release calcium carbonate into the aquarium water at a slightly faster rate than normal. A layer of plastic or fiberglass screen should always be placed on top of the course substrate or the plenum. The purpose of the screen is to prevent deep burrowing fish or invertebrates from disturbing the bottom layer of the DSB, and releasing hydrogen sulfide gas, acidic water, or nutrients into the aquarium.

The Second Layer:The second layer should consist of a layer of aragonite sand, roughly 1" to 2" inches in depth with a particle size of about 2 to 3mm. Either "live sand" or dry aquarium sand can be used for this layer, if dry sand is used however, it should be seeded with true live sand (not the bagged live sand) aquired online or at your LFS, in order to introduce the desired microfauna and bacteria required to maintain the DSB long term. A second plastic or fiberglass screen may also be added at this point.

The Final Layer: The final layer should consist of an 1" to 2" of very fine sand with a particle size of 1mm or less. Some prefer to use "sugar sand" for this layer, and live "mud" is sometimes used for this final layer in some remote DSBs. Again, the introduction of desirable microfauna and bacteria is required.

Hope it helps.

As to your question on the aragonite sand, it is constantly breaking down in the reef tank, however in the normal pH of our reefs the breakdown is a slow process.

 

[BallinCrew10]

****, and here I was thinking I could just add 6" of aragonite and call it a day haha.

 

[BallinCrew10]

Whoops...dang* haha

 

[Gti_Leo]

i've never seen anyone use a plenum in a DSB.

this is all pretty new to me

this is the link i've used

http://www.reef-eden.net/DSBs.htm and http://www.ronshimek.com/deep_sand_beds.html

 

[Hondatek]

The plenum seems a little to advanced for me. The combo of course and fine sand seems like the best way to go .

 

[BallinCrew10]

i've never seen anyone use a plenum in a DSB.

this is all pretty new to me

this is the link i've used

http://www.reef-eden.net/DSBs.htm and http://www.ronshimek.com/deep_sand_beds.html

Very good links, A LOT of info. When I move in the spring, DSB it is lol.

 

[AquaRick]

Little something I put together a while back on a DSB, might help you with some of your questions.

Set-up:
A properly set-up DSB consists of three distinct layers, each ranging from 1" to 2" or more in depth.

This image has been resized. Click this bar to view the full image. The original image is sized %1%2.

The Bottom Layer or Plenum: The bottom layer in a DSB can be set up in one of two ways; either a plenum or a layer of very course substrate. This bottom layer is the anaerobic portion of the DSB, and anaerobic bacteria, similar to those found living deep inside the pores of LR, are found here. These anaerobic bacteria complete the nitrogen cycle, by converting nitrates into harmless nitrogen gas. Hydrogen sulfide gas is also produced as a result of this conversion, creating slightly acidic conditions in this area. Generally this deadly hydrogen sulfide gas is broken down within the anaerobic area, however, if this deep layer is disturbed by the hobbiest or deep burrowing fish or invertes, this gas, the acidic water, as well as any trapped nutrients may be released causing the aquarium to "crash."

The Plenum
A plenum is created using an undergravel filter or eggcrate covered with a layer of plastic or fiberglass screen supported above the bare aquarium bottom by inert spacers such as PVC or plastic pipe. The plenum creates an open water space 1" to 2" inches deep.

Plenum for a remote DSB

This image has been resized. Click this bar to view the full image. The original image is sized %1%2.

Bottom of the Plenum

This image has been resized. Click this bar to view the full image. The original image is sized %1%2.

Course Substrate
In the event that a plenum is not used (and research has shown that there is no significant benefit to using or not using a plenum with DSBs), the bottom layer can consist of a 1" to 2" layer of course sand, CC gravel or crushed shell; regardless of the substrate used, the material should be course enough that the layer is very porous allowing bacteria to colonize and water to diffuse easily. Using aragonite sand, CC, or crushed shell also allows these substance to break down in the slightly acid conditions of this layer, and release calcium carbonate into the aquarium water at a slightly faster rate than normal. A layer of plastic or fiberglass screen should always be placed on top of the course substrate or the plenum. The purpose of the screen is to prevent deep burrowing fish or invertebrates from disturbing the bottom layer of the DSB, and releasing hydrogen sulfide gas, acidic water, or nutrients into the aquarium.

The Second Layer:The second layer should consist of a layer of aragonite sand, roughly 1" to 2" inches in depth with a particle size of about 2 to 3mm. Either "live sand" or dry aquarium sand can be used for this layer, if dry sand is used however, it should be seeded with true live sand (not the bagged live sand) aquired online or at your LFS, in order to introduce the desired microfauna and bacteria required to maintain the DSB long term. A second plastic or fiberglass screen may also be added at this point.

The Final Layer: The final layer should consist of an 1" to 2" of very fine sand with a particle size of 1mm or less. Some prefer to use "sugar sand" for this layer, and live "mud" is sometimes used for this final layer in some remote DSBs. Again, the introduction of desirable microfauna and bacteria is required.

Hope it helps.

As to your question on the aragonite sand, it is constantly breaking down in the reef tank, however in the normal pH of our reefs the breakdown is a slow process.

Great info here! Thanks again!

 

[Wy Renegade]

****, and here I was thinking I could just add 6" of aragonite and call it a day haha.

I've seen them done that way, but I don't think they are as successful. One of the new recommendations with DSBs is that you exchange the sand every few years on a portion of the sandbed in order to prevent the binding of undesirable inorganic substances.

i've never seen anyone use a plenum in a DSB.

this is all pretty new to me

this is the link i've used

Deep Sand Beds and Ron Shimek's Website...Deep Sand Beds

Plenums where used under some of the very first DSB systems that were tried on reef tanks, and for awhile there was a lot of debate over the benefits of using them vs. not using them. Later research seemed to substantiate the fact that there is no additional benefit to using the plenum system. In the U.S., most people have moved away from the plenum to just a DSB, so many hobbiests who have gotten in in recent years are unfamiliar with the concept.

The plenum seems a little to advanced for me. The combo of course and fine sand seems like the best way to go .

It is my preferred method as well, especially since there is no proven additional benefit to using the plenum.

 

[Hondatek]

So I have eggcrate on the bottom of my tank. So I'm thinking 3 inch coarse sand bed with a 4 inch fine bed on top. That sound good?

 

[Wy Renegade]

So I have eggcrate on the bottom of my tank. So I'm thinking 3 inch coarse sand bed with a 4 inch fine bed on top. That sound good?

How large of a tank are we talking? Personally, I would do about 1/4 to 1/3 course, and then the remainder with fine. In a smaller tank, I would keep total depth between 5 and 6 inches, in a larger tank you might get away with 7". I've seen were some people use a 5 gallon bucket completely full of sand in their sump area so they can take it offline, but since DSB are more about surface area exposure, I doubt they get much real benefit.

 

[Hondatek]

It's a 180 gallon tank.

 

[Wy Renegade]

It's a 180 gallon tank.

In a 180 a 7" sandbed will be fine.

 

[coffeetwitch]

I read somewhere, I really need to keep track of where I read all this, that 5" dsb was optimal. If that is true 2" on a 180 is alot of extra cash. Well, depending on substrate.

 

[Hondatek]

I do that too twitch . I read to much and forget where I read it. I would of course like to save money if I can . On the other hand I don't really want to skimp on this tank.

 

[Wy Renegade]

Your not the only ones, I do that quite often. Then later I'm looking through a list of favorites a mile long trying to remember where I came across something.

Some basic information and a couple links that you might find of interest in regards to sandbeds in general.

Shallow vs. Deep Sandbeds: Generally speaking, 1/4" to 2" is considered to be a shallow sandbed (SSB) and 3 1/2" to 6" is considered a deep sandbed (DSB). Generally the area between the two is considered to be an unsafe zone, not quite deep enough for anaerobic bacteria to establish and carry out denitrification, but too deep for aerobic bacteria to be present, thus allowing the build-up of toxic wastes in the form of hydrogen sulfide gas which can be released if the sandbed is disturbed.

It has generally been accepted that SSB, like CC, maintain oxygenated water throughout the sandbed and therefore must be maintained by syphoning, generally on a monthly basis. While DSBs on the other hand have an anaerobic area (typically in the bottom inch or two) very similar to Live Rock, in which anaerobic bacteria are able to establish to help break down nitrates. The DSB requires little to no regular maintainence (some do regularly siphon or stir the top inch or so). Recent research however indicates that both shallow and deep sandbeds function in converting organic waste into free nitrogen gas. I've attached a link to the two articles that report these finding below.

Feature Article: An Experimental Comparison of Sandbed and Plenum-Based Systems. Part 1: Controlled lab dosing experiments — Advanced Aquarist's Online Magazine

Feature Article: An Experimental Comparison of Sandbed and Plenum-Based Systems: Part 2: Live Animal Experiments — Advanced Aquarist's Online Magazine