Christopher Marks

Deep Sand Bed vs. Bare Bottom

73 posts in this topic

No one has even mentioned crushed coral. I've had about a 2" base of crushed coral in my BC29 for about 4 years. I clean it occasionallly with the siphon (where I can get to it without moving rocks or corals). With the exception of a little green hair algae that just popped up recently, I haven't had any problems with it. I like the look, and mushrooms and my green star polups will grow in it. Am I alone using crushed coral?

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BB for me. I've painted the underside sand color so it looks like it has a sand bed but stays spotlessly clean. My long term goal isn't to keep the bottom bare through - I want to cover it in different corals :D

 

115114.jpg

 

Krylon Fusion?

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ive used DSB's and always had algae problems, my new setup is going to be barebottom with a refugium/plenum, i'd also like to add that replacing sand with live rock is somewhat a double edged sword as well, the more rock, the more dead spots for detritus to collect and less turnover of water, essentially you need to find a balance of biological surface to water, both have disadvantages.

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i always run my tanks with crushed coral/live sand at about 1-2" thick

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Krylon Fusion?

 

Yes.

 

I moved everything in this tank into my 40B which is also BB. Today was my bi-weekly maintenance day. Turned off the flow. Turkey basted the rocks. Blew the rock poo into one corner. Sucked it all out. Replaced with new saltwater. Done. Spotless tank. No algae = snails are starving to death = had to move them to dirtier tank!

 

Happiness :D

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Yes.

 

I moved everything in this tank into my 40B which is also BB. Today was my bi-weekly maintenance day. Turned off the flow. Turkey basted the rocks. Blew the rock poo into one corner. Sucked it all out. Replaced with new saltwater. Done. Spotless tank. No algae = snails are starving to death = had to move them to dirtier tank!

 

Happiness :D

 

Care to PM me the color you used, if you know.

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I made this a few years ago. Here is the full article: Deep Sand Bed -- Anatomy & Terminology

 

DSB.jpg

 

Personally, I like the look.

 

dt_3_months_after_cycle.jpg

 

Can still work in a nano, you just have to maintain it right. There are a number of theories on how best to maintain a successful DSB. Look to the linked article for some general rules of thumb.

 

It's worth mentioning that I've never had detectable nitrate. No rotten egg smell either. :)

Edited by Whys
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I have a remote sand bed in my fuge, but I basically have a bare bottom tank. There is rubble and a little bit of sand dusted around to hide the glass bottom.

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Here are some links to the only experiments I've seen looking at different substrate setups. The tanks they used were 3 gallons each, so this should be relevant to nano reefs. They seem to conclude that shallower sand beds are worse and that plenums don't do anything noticable.

 

These are by Rob Toonen in Advanced Aquarist:

 

An Experimental Comparison of Sandbed and Plenum-Based Systems. Part 1: Controlled lab dosing experiments

 

An Experimental Comparison of Sandbed and Plenum-Based Systems: Part 2: Live Animal Experiments

 

Skip down to Overall Summary for their conclusions.

 

Also Eric Borneman wrote an interesting article here:

 

The Old Becomes New, Yet Again: Sandbeds and Vodka

I am new to this forum and new to this hobby, having only dabbled briefly in the late '80's. I do not have a background in marine biology, but I do have one in science and the scientific process. These links you provided were a breath of fresh air....my bs meter was getting overworked surfing the web for real facts as opposed to anectotal stories. At one point I was thinking that this is a pretty large communtity in an area where there is still a lot to be nailed down....we could do some experiments! Then, just considering the gadzillions of uncontrolled variables.....ferget it. I haven't even got my tank yet and am finding these decisions like what kind of sand bed is best daunting. It's a dang good thing I'm not in a hurry. I get the feeling that every decision I make will require hours of research. That's OK though, it's actually half the fun. Keep these debates rolling...very interesting.

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From everything I've read, I'm kind of leaning toward the DSB. I was reading some interesting stuff about growing sea grass. A minimum depth for the sand base would be 4" for some, 6" for others. This one article mentions the top 2" should be aragonite, silica, or calcite sand (forgot to note granual size) and the bottom 2-4 inches should be some sort of mud mixed with aragonite or silica sand into a loamy media. I don't know if exact proportions were mentioned. Those aticles stressed not disturbing the top layers of the sand....definitely don't stir it or vacuum it....but to keep it looking spiffy use snails and stir the water over the sand when doing water changes to have your filter take up some of the surface stuff.

 

http://reefkeeping.com/issues/2006-04/sl/index.php

 

She does recommend gobies and such to stir up the topmost layer of sand, but if you are interested in growing grass, get them after the grass is established so they don't plow it up.

 

That's a link to an article about sea grass that was very good and also had a wealth of info on the sand bed. I'm thinking "mud, that can't look very pretty," but then I think about terrariums I've had....it didn't look so bad. In my mind, I'm setting up at least a portion of my tank to support sea grass, although not really interested in the entirely planted tank that some are doing.

 

 

 

 

 

BB for me. I've painted the underside sand color so it looks like it has a sand bed but stays spotlessly clean. My long term goal isn't to keep the bottom bare through - I want to cover it in different corals :D

 

115114.jpg

I love how you have your rocks! Very pretty.

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From everything I've read, I'm kind of leaning toward the DSB. I was reading some interesting stuff about growing sea grass. A minimum depth for the sand base would be 4" for some, 6" for others. This one article mentions the top 2" should be aragonite, silica, or calcite sand (forgot to note granual size) and the bottom 2-4 inches should be some sort of mud mixed with aragonite or silica sand into a loamy media. I don't know if exact proportions were mentioned. Those aticles stressed not disturbing the top layers of the sand....definitely don't stir it or vacuum it....but to keep it looking spiffy use snails and stir the water over the sand when doing water changes to have your filter take up some of the surface stuff.

 

http://reefkeeping.com/issues/2006-04/sl/index.php

 

She does recommend gobies and such to stir up the topmost layer of sand, but if you are interested in growing grass, get them after the grass is established so they don't plow it up.

 

That's a link to an article about sea grass that was very good and also had a wealth of info on the sand bed. I'm thinking "mud, that can't look very pretty," but then I think about terrariums I've had....it didn't look so bad. In my mind, I'm setting up at least a portion of my tank to support sea grass, although not really interested in the entirely planted tank that some are doing.

 

 

 

 

 

 

I love how you have your rocks! Very pretty.

 

 

I have to wonder if seagrass is like FW aquatic plants. In the FW world, you can have very deep substrates if the tank is well planted as the plants "pump" oxygen to their roots which oxygenates the substrate. this obviously kills anaerobic bacteria, but also keeps from having any issues with a DSB.

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I was kind of thinking along those lines. I was also thinking that sea grass and plants should be part of a balanced ecosystem. But I'm not sure. In my snorkeling adventures in the Caribean and Hawaii (I'm old, I've been a few places), I recall seeing sea grass and seeing coral reefs, but not in the same place. A meadow of grass over there, corals over here. Makes me wonder if it's such a great idea to attempt both in the same 28 gallon tank. I think I'll try....I can always take the grass or plants out if it isn't working.

 

Getting off topic though....sorry.

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Getting off topic though....sorry.

 

I disagree. What you're discussing sounds perfectly relevant to the topic. Unlike kelp, sea grass is in fact a real plant, roots and all.

 

I once asked a marine biologist about kelp and learned that kelp and sea grass do in fact grow separately from corals. I don't remember the reason, or if one was given, but if I were to guess, I'd say nutrient levels are likely to blame.

 

How can one have the same water in the same system with two different nutrient levels? I'm guessing a very slow flow between two systems would be the right way to start.

 

Hmmm... how big would a system have to be to encompass everything from the fresh water stream, to the brackish marsh, coral reef, and sea grass sea bottom? Okay, now we're off topic. :D

 

Look here.

Edited by Whys

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Oh, that's neat!

 

Thanks. Still learning my way around here.

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I use both depending on the tank. I have used both with success. I find that after 72 hours of chanting and swaying, the answers come.

in my current nano project a 5 gal 6 weeks old. a standard 5 gallon is too shallow for a proper DSB regardless of the media used. proper bed should be 4+inches to work some say 3 i say more the merrier. and I love the DSB. i tried a DSB in this little tank at 3 inches using a DSB plenum hybrid that has worked well over my years of fish/reef. it became a nitrate factory it just wasnt deep enough for the anaerobic zone needed. and the proper depth would have left me with 5~ inches of water space before putting in rock. so DSB is a no go in shallow tanks. I have a 15 tall that has been up for 4 years with a 4 inch sand bed coarse sea floor from carib sea on bottom 1inch then bridal veil layered and Bahama sand for the rest any live sand of similar size will work. for DSB or Plenums to work they must be set up right and DEEP ENOUGH or they will wreak havoc and drive you ape s&^%. in my large reefs i use the same DSB method as do most all public and educational facilities. shallow IE under 15 inches high use shallow bed that you can vacuum out debris efficiently.

bare bottom vs shallow bed even a shallow bed will give you more areas for beneficial bacteria to colonize helping with stability, a bare bottom doesnt have that but you can see if you missed anything. best thing to do is watch your tank test the water frequently especially if something looks off. do research, learn about things you would never do just to know why it wont work and the things that will. then common sense will go a long way with the research.

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Bare bottom seems to have its advantages, but it is soul-less! I've actually switched back to shallow sand beds from using a DSB, dsb is just a detritus trap, nitrate is easy to control I think in any tank, phosphates are the tricky part.

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Old, but useful thread IMO.

I'm fine with BB, SS, or DSB, but they have to be used correctly.

BB (0in) - If the bottom get's covered in coralline and corals it looks great IMO, but if not, it RUINS any tank. Plus what fish wants that?!

SSB (1-3in) - If you keep it clean it looks awesome.

DSB (4+in) - Keep the top clean and make sure you don't dig around in it, I prefer them in fuges vs DT because they take up a lot of room and don't look very nice from the side sometimes...

I like a 2-3in SSB in the DT with a 4-6in DSB in the fuge(Usually a display fuge :) ), with mangroves and seagrass and macro growing everywhere.

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Some one should turn this into a poll. It would be fun to see how people are thinking now. Ideas change all the time.

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Old, but useful thread IMO.

I'm fine with BB, SS, or DSB, but they have to be used correctly.

BB (0in) - If the bottom get's covered in coralline and corals it looks great IMO, but if not, it RUINS any tank. Plus what fish wants that?!

SSB (1-3in) - If you keep it clean it looks awesome.

DSB (4+in) - Keep the top clean and make sure you don't dig around in it, I prefer them in fuges vs DT because they take up a lot of room and don't look very nice from the side sometimes...

I like a 2-3in SSB in the DT with a 4-6in DSB in the fuge(Usually a display fuge :) ), with mangroves and seagrass and macro growing everywhere.

What you've described is pretty much my plan for my tank. Enough sand in the display tank to make things look reasonable, but then get serious with the biological function aspect of the fuge.

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I considered a bare bottom with my 37 but it just didnt look right to me. I wanted a more 'oceanic' look so I went with a 1" base of aragonite, some live rock with red dragon tongue algae and a standalone leather coral. I tossed in a half dozen shells used for hermit crabs and stood one large clam shell up between the rock and leather. I like the look of it now and my clown fish has claimed the coral for his bed (I really see him lying at the center sometimes when I first turn on the lights) and the others have found homes in the crevices of the rock.

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Overall I'm happiest with shallow.

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started with deep sand bed & switched to bare bottom & love it.

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