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gwen_o_lyn
02-27-2006, 05:52 PM
So after finally catching up on the boards today *it's so freakin busy here!!!* I realize that a lot of you are on the DSB bandwagon with Rob. :rolleyes: So where are those SSB people and BBers??? SPEAK UP!!

What are you folks gonna do when your DSB CRASHES!?!?!? ha ha ha :twisted:

Reefbaby
02-27-2006, 06:13 PM
Well...at the moment, I'm kind of barebottoming it with a bit of sand...it's wrong all the way...can't wait to get a DSB in!! I'm with Rob all the way!

AdamJ
02-27-2006, 06:15 PM
i guess i see it thru different tinted glasses and see the dsb as the closer mimic to what exist in real life.

if / when my tank's dsb crashes, its just another reminder on how we do our best to recreate nature (mostly) in our tanks but fail to some degree.

JustDavidP
02-27-2006, 07:01 PM
I've used DSBs in all my tanks and haven't had a problem... yet.

I also fear the "what if" but had horrible problems keeping other tanks stable without DSB.

Ciao for now...

D

Rob
02-27-2006, 08:39 PM
What are you folks gonna do when your DSB CRASHES!?!?!? ha ha ha :twisted:

I'm with Rob, he's so smart.. :D lmao...

how many people do you know (first hand) that have had a true DSB crash
as i have mentioned, a properly balanced tank can handle a sand bed disruption. so they are NOT as sensitive as you are making them out to be...

i am not saying DSB are the only way to go, im just saying they are the best FOR ME and i have had many years of success with them

my clown tank has a SSB, and i do have issues there.. not real shallow (about 3") but there are so many other things that could be causing that...lol like the fact that they are fed 3 times a day...lmao

Scott
02-27-2006, 08:45 PM
I guess I had to vote SSB, I didn't know any better when I setup my (first) tank 6 months ago.

Looks like I only have around 2" in the display (20lbs). Now, I can be lectured to about the sump/fuge I setup as that was much more recent. Again, I only put in 20lbs of live sand, which is 3" deep. I'm sure I'll go DSB when I setup another tank.

Isn't everything you do in your first tank excempt anyhow? :rolleyes:

DJGonzo69
02-28-2006, 01:00 AM
How Deep is Deep, & how shalow is shalow? I'll vote when i get answers.
Thx,
John

Rob
02-28-2006, 01:44 AM
just to draw the line, we will say less than 4" is shallow, 4" or more is deep

8251Reefer
02-28-2006, 02:43 AM
Right now I am half and half, half of my tank is about 3 inches in the front sloping to about 4 in the back and the right side slopes up to about 5-6 inches with 4 inches in the back, it looks cool like that imo...

JustDavidP
02-28-2006, 11:53 AM
For what it's worth...my two year old, 75G reef had many an occasion when the powerhead fell or whatever, and resulted in a dredged sand bed. I had no problems whatsoever. I had MORE issues when the clams died in my system. My sand bed was just NASTY with all kinds of cyano and stuff at the glass. It was so full of gasses, that from time to time, I'd use a skewer to release the bubbles. Again, when it did get dug up after two years idle..I had no issues.

D

DJGonzo69
02-28-2006, 02:39 PM
Thx Rob. Well looks like i'm in the SSB category. I have about 2-3inches in my 30gal. tank.

RazerCorals
03-01-2006, 11:05 AM
SSB and BB fan here :)

INKMAN
03-01-2006, 05:37 PM
About 5 to 6 inches in the bottom of my 150. That is about 210 lbs. My tank is deep so I need all the help I can get to bring my corals up closer to the lights.

I don't know enough to tell wheather this is good or not but I thought I would add my $.02.

Peace,
INKMAN

Amphibious
03-02-2006, 09:04 PM
I recently explained my method of doing a DSB, which is a little different than the norm. You can read it here, if you are interested.

DSB - thread (http://www.talkingreef.com/forums/showthread.php?t=401)

It has been successful for me for the past 10 years or so.

pham411
03-04-2006, 10:46 PM
wait wait wait...... can dsbz crash?.... im a dsb guy. about 5 or 6 inches in my 75g. i believe it was about 100lbs.

gwen_o_lyn
03-06-2006, 02:55 PM
wait wait wait...... can dsbz crash?.... im a dsb guy. about 5 or 6 inches in my 75g. i believe it was about 100lbs.

Here are some links for reading- I thought someone would jump in on your question, but maybe not.

http://thereeftank.com/forums/showthread.php?t=43963&highlight=DSB+crash
http://thereeftank.com/forums/showthread.php?t=48246&highlight=DSB+crash
http://thereeftank.com/forums/showthread.php?t=23293&highlight=DSB+crash

Rob
03-06-2006, 04:09 PM
im sorry, i thought i had responded to this one... (need to pay more attention..lol )
Pham, to answer your questions.. can a DSB crash? absolutley, but you can have a system crash in ANY scenerio, and havinga DSB doesn't raise your chances.. IMO, it provides a much more stable system (but thats just my opinion)
Basically what this means is that the DSB stops functioning for one reason or another, and either stops or can no longer proccess the nutrients. this situation usually happens quick, but IMO is not that common...

Personaly, I have found that having a good amount of sand dwelling/cleaning/stiring critters can really reduce any chance of this happening. items like sand sifting stars/gobies, Nauss snails, tiger tail cukes, etc.. this allows the nutrients to be efficiently transfered to and from the DSB.

Personally, and though some anecdotal research, there is some evidence that shows that infrequent sand bed disruptions can help prevent this also..

There are some people that think that if you have a DSB, it can NEVER be disturbed, this is not true and may actually lead to a crash, but personaly, i think that once or twice a year, a semi-major disruption to different areas of the sand bed will help rejuvinate it..

For example, in Jauary, you turn over a bunch of sand in a specific area of the tank, and in july you do the same thing in another(different) area.. again, i have to scientific evidence on this, but there many things about it that makes sense. it also provides a little boost in take food levels that your filter feeders will love.. :)

gwen_o_lyn
03-06-2006, 06:41 PM
I like your deep sand bed theory Rob. I agree that as long as it gets decent disruptions every so often, then you are ok. I do wonder about tanks that receive no sandbed disruptions, however.

Jimm
03-06-2006, 07:12 PM
I'm one of those who stirs the DSB up to get all of that good bacterial stuff back up into the water column to feed the corals. So I'm not very worried about a sand bed crash.

Amphibious
03-06-2006, 08:13 PM
Gwen-O-lyn

I agree that as long as it gets decent disruptions every so often, then you are ok. I do wonder about tanks that receive no sandbed disruptions, however.

Gwen-O-lyn, that is the whole point of being successful with DSBs. Do them right and they are fine. Neglect them and, like anything else neglected, disaster is the result. It's a matter of maintenance! If you didn't do maintenance on a BB you would experience disaster.

In my tank thread, Amphibious' 135 gal (http://www.talkingreef.com/forums/showthread.php?p=5818#post5818) I give my method of setting up a DSB to keep it healthy. I do not set my LR on top of the DSB. That's asking for a crash some where down the road.

In addition to this method I also stir it up monthly. Not the whole bed but parts of it. I use a piece of 3/4" OD rigid plastic pipe, available at most LFSs. By putting my thumb over one end, sinking it into the sand and releasing my thumb, the sand come up the pipe. Then I slowly release the sand and the resultant cloud of "stuff" disapates through the tank and feeds my filter feeders.

Jimm has the right idea. And, he's right in not worrying about a DSB crash. It's all about doing the proper maintenance.

Rob
03-06-2006, 10:50 PM
Dick..
great example of DSB maint.. thanks, i will try that out in the future... :)

Jimm
03-06-2006, 11:25 PM
I do the same thing that Dick does with his LR too. Mine are sitting on small pieces of rubble though not PVC. The pieces of rubble sit on the bottom of the tank. The LR sits on the rubble. The aragonite sand comes up to just below the LR although mine looks like it's sitting right on the sandbed. It's not quite as good as what Dick is doing. In my next tank I will raise them up a bit to get a little water flow under them.

JustDavidP
03-07-2006, 10:29 AM
I too use a tool to stir my DSB. In my case, it's a broken toy pool stick that is plastic and about 3' long. I simply 'rake' the sand at a depth of about 1/4 inch or so. I also release large gas bubbles that I see. I don't go too deep, but I move some sand none the less.

Yes, there is some benefit to the filter feeders when you do this. In my old 75, my corals and feather dusters would react positively when I stirred my sand up. For what it's worth, I also use a powerhead, monthly, to blow the heck out of my live rock. It makes a SNOWSTORM in the tank. This too puts the waste into the water column for better filtering and use by the filter feeders. Heck, there are products out there labeled as "Snow" and such that are nothing more than the same 'sediments'.

Finally, I also noticed a positive reaction by my clams and other filter feeders when I clean the film algae off the glass.

All in all, there are many 'natural' ways to stir up foods in the system AND benefit your sand bed and rocks at the same time.

Dave

Reefbaby
03-07-2006, 05:33 PM
I think I already know what your guys' answer to this question will be, but nevertheless....

I've done some searches on other sand-sifting critters and was wondering what your opinion was on horseshoe crabs (probably too clumsy, huh?) or fish such as flounder or other fish that like it get in under the sand??

gwen_o_lyn
03-07-2006, 11:13 PM
I don't recommend a horseshoe crab for a reef tank. They tend to like lower temps under 75*. They are also very clumsy and tend to knock things over. Mine only lived about 6 months- I think it may have starved in my tank, but I don't know for sure.

Wrasses or sand sifting gobies are nice to help move the sand around.

Amphibious
03-07-2006, 11:50 PM
gwen_o_lyn

That's really good advice that I concur with.

And, by the way, I really like your new avatar! 8-)

gwen_o_lyn
03-08-2006, 12:24 AM
thanks......

Reefbaby
03-08-2006, 04:09 AM
Yeah - that's what I thought you guys would say about the horseshoe crabs. I've heard they just mow everything down and that they can starve quite easily.

How many gobies could one keep together, or rather how many pairs of different ones? With my new setup (425g), I'd like to get a fair number of critters that will take care of the sand bed.

Clayman
03-20-2006, 01:31 AM
I have a 4" DSB. Mostly I like the look of sand, Also some of the creatures I have perfur sand and like the fighting conch ( my fav ) needs a DSB to thrive.

Amphibious
03-20-2006, 01:49 AM
Clayman

http://www.theculturedreef.com/welcome.gifTo Talking Reef.

Clayman
03-20-2006, 02:05 AM
Thanx. Just linstening to the podcasts now.

Scott
03-26-2006, 01:37 PM
any idea what kind of cycle a tank would go through if one added more sand to a tank? I don't know if I'd do it, but it has crossed my mind a few times to add more sand to my tank, or even my sump/fuge. The tank has maybe 2" of sand and the fuge has just over 3". If I were to add more sand, think it would have a little to no cycle effect?

gwen_o_lyn
03-26-2006, 09:50 PM
You can add sand at any time.

kj_yoda
03-26-2006, 11:29 PM
I have added sand from time to time, as needed, based on cleaning. haven't had a problem, as gwen said

Reefbaby
03-27-2006, 05:18 AM
In most of the books, they also always recommend adding more sand from time to time, especially since aragonite sand will get broken down/utilized and the sand bed layer will grow thinner over time. I've never heard of it causing a cycle and it probably wouldn't as long as it wasn't a bucket of previously "live" sand that had just recently died....

Rob
03-27-2006, 12:16 PM
problems and/or cycles can occur if you have and existing functional DSB, and then you cover it with a new deep layer of sand. the problems arise becuase you smother ther upper most layers of inhabitants. Remeber for the substrate shows, these layers contain aerobic bacteria and other life that needs light, oxegen, adn needs to be able to fairly freely. when you add more sand, if you add too much you almsot instantly conver this zone to an anaerobic zone, which can lead to die off.

while this can range in severity, my normal recommendations is to add about .5" at a time. im sure you can get up to about 1" at a time, but have not done it

also, Christi's statement is right, expecially with agronite sands, as they buffer the water they slowly disolve calcium into it, causing the sand bed so slowly disolve, so it does need to be replenished from time to time

Scott
03-27-2006, 10:37 PM
ok so with the really shallow sand bed in my display (~2") it really wouldn't impact it. But with my fuge, it's border line DSB (3") I'd want to add more slowly over time just to be on the safe side.

Thanks!

JustDavidP
03-28-2006, 10:23 AM
I've simply "Moved" smallish (1/8 of the bed) areas aside, put new sand down, and covered it with the "live" sand that was put aside. If you have a larger, healthy, or established system, this can be done with little effect. If you disturb too much of an area, you can cause problems by releasing the nutrients, gasses etc. and could cause a tank crash. If you have a smaller system, move in smaller steps. Space out the addition of sand over a period of weeks if not months and do very small sections at a time.

This works for me. Chime in if you think this is the WRONG thing to do...and why you think so. It'd be good discussion.

D

Amphibious
03-28-2006, 10:35 AM
I concur with David, this is the method I have used for years.

JustDavidP
03-28-2006, 10:44 AM
Danke Richard! I have always been known as a "rogue" in the hobby. I push limits often. I didn't know if others did this "fractional" replenishment of sand like I did or not.

D

kj_yoda
03-28-2006, 10:48 AM
I like Dave's idea of moving sand, adding more, then covering it with the live sand. That should eliminate any problems with aerobic bacteria and such.

JustDavidP
03-28-2006, 11:00 AM
BUT...again...remember to do it slowly and in small sections. Picture your sand bed like a geographical/archaeological "Survey Site" and picture it in "quadrants" of sorts. Do one little section at a time, based upon the health of the sand bed, the size of the sand bed, and your overall comfort level. Take your time.

D

Scott
03-28-2006, 09:15 PM
Thanks everyone, I think I may try this to get a little deeper sand bed.

Now the question is, how long can I keep an opened bag of live sand? I think I remember seeing the shelf-life is like 12 months. But I'm assuming that is if the bag is not opened.

Reefbaby
03-29-2006, 06:09 AM
Sorry Scott...just had to share....this is pretty funny....this is what showed up in my email when I got your post:


Now the question is, how long can I keep an opened bag of live sand? I think I remember seeing the shelf-life is like 12 months. But I'm assuming that is if the bag is not opened.
opened
opined
upend
oped
owned
Edit...
Revert to "opned"

:-) Made me smile!

Scott
03-29-2006, 11:39 AM
Christi, totally forgot about the email notifications after a post....and I get them all the time so I know when something was posted! Ugh...selective memory maybe? :rolleyes:

I went against what I posted in the preview thread, and installed the google toolbar out of curiosity. Then I needed to test it, so I misspelled "opened" to see how the toolbar worked. But the dropdown for correct spellings, and to turn it off, didn't quite play nice in the "quick reply" box....and it posted the drop down and all! :rolleyes: LOL

So I did a quick edit to get rid of that....but didn't think about the email notifications. way too funny!

Of course playing with it now....if I use it, I can't figure out how to turn off the check either...and it would have done the same thing!

Rob
03-29-2006, 11:57 AM
lol.. looks like scott is using the google toolbar, and had the full WYSIWYG editor on in the forums...

its happened to me a few time...lol

Rob
03-29-2006, 11:58 AM
Scott, if you go into your UserCP and not use the WYSIWYG and use the advanced... the middle option between WYSIWYG and simple...
you wont have that problem

Scott
03-29-2006, 11:59 AM
yeah, I tried it out after all. I posted that in the preivew thread...Rob, you can help me there. LOL

Scott
03-29-2006, 12:05 PM
Ok, I went to the standard editor....no more WYSIWYG.

Hey, that makes is so much difference! especially with that spellcheck stuff...don't have to worry about how to turn off the spellcheck!

Scott
03-29-2006, 12:06 PM
Hey, that makes is so much difference!

Ok, now I just need a grammer checker and something to make sure what I type makes sense when you read it! LOL

fat walrus
07-27-2006, 04:35 AM
how did this pop up as a new post?

Amphibious
07-27-2006, 08:20 AM
Not sure but, my guess is that somebody voted but didn't actually post a response.

NaClFinatic
07-27-2006, 09:52 AM
Yes, I think that is what happens. I noticed it on the Snails & Hermits poll.

And BTW, I plan to be a deep guy

Rob
07-27-2006, 11:30 AM
yep, thats what happens, when someone votes, it will tag it as unread, and then show up in the new post list

Small Fry
07-30-2006, 08:52 PM
well i have yet to respond, i dig display tank space, so ssb for me, BUT, i plan to have a 100g sump with a dsb (also known as a remote deep sand bed last i checked, where was that on the voting list???)

CarmieJo
07-30-2006, 10:47 PM
For the purpose of the poll I think it would be packaged generically with DSB.

Amphibious
07-30-2006, 11:39 PM
I have to agree with you Carmie. If you have a DSB anywhere in the system then it's working it's magic.

V
10-19-2006, 06:37 PM
the for and against list is as long as my virtual arm here. at the moment we are drawed into the conclusion by some die hard fans of DSB that they are more benifical that the rest! i know its from the perspective of functionality, and believe me, im fully aware of items that are functional:huh:, only problem is after all this time, years of experience and countless years researching on topics of this sort, im still undecieded on the subject.
what i do believe is any sand is better than no sand, and that its a growth pit for bactera ,period! being thats theres more of it in volume always begs the logical question, is it more effecient with twice the culture and how is the sand mechanism changed with that extra inch of covering?. being remote or not is nothing, cause as long as the waters still flowing it doing its job!

thanks for not http://www.alexander-oberg.de/smileys/firedevil.gifflame throwing my way, or i might need you firefighters to put me outhttp://www.alexander-oberg.de/smileys/fireman_2.gif sledgings ok though..lol

fat walrus
10-28-2006, 01:29 AM
Let this thread die. Start a new one if need be.

V
10-28-2006, 07:07 AM
it would have if u didn't pipe up again!http://www.alexander-oberg.de/smileys/00000020.gif

stang5_o2002
11-11-2006, 07:25 PM
Despite my vote (forever ago) My 16 gal bow has been BB for a little over a week. I LOVE IT. Algae is gone, no more funky smell from the water. Corals look better than ever.

V
11-12-2006, 09:38 AM
Give that http://www.green-eyed-monster.com/scratchy_chimp.gif chimp a banana..bowed & pealed, not mashed lol

vanmo92
11-15-2006, 04:47 PM
i like my DSB

ReeferLogan
11-15-2006, 07:34 PM
DSB's imo do very nicely to help stabilize systems, however like anything else do require maintenance (stirring, fractional replacement, etc.). The 24g I set recently does have about +4" as well as a "plenum"* and my 180 is "dsb" w/o plenum, however have 2 29s w/ssb, one with attached dsb refugia, the other not. The 29 w/o attached 'fuge actually looks better, but has a much lower bioload (a single nemateleotris decora) vs 5 various ones in the other.

*idk if anyones used this one before, but for small tanks i take a large media bag like 8x12 or whatever fits best and put double or triple layers of properly trimmed "eggcrate" panels held together with plastic zip ties. Insert into bag, tie it tight, drop in and cover with sand. Instant plenum. This can be used in a modular fashion as well by grouping multiple bags.

my .o2 worth

Logan

Amphibious
11-15-2006, 07:44 PM
Me to. wouldn't be without one.

Reefbaby
11-16-2006, 05:57 AM
Welcome to TR ReeferLogan! Thanks for sharing!

Seahorsedreams
11-16-2006, 03:39 PM
Is there a voting option for one person using a barebotton, a DSB and a shallow SB? I'm using all three at the moment.

Astrivian
11-16-2006, 05:40 PM
So let me throw in my info. Since i am so new to all of this, i can't speak from experience, but most of what i have read (3 books, TR threads, wetwebmedia stuff, reefkeeping stuff, TR casts, etc.) the DSB seems to be the way to go if you do the necessary maintenance. I agree with Amphibious here; all things require some upkeep.

Having said that, i cannot do a DSB in my new 100 gallon tank (http://www.talkingreef.com/forums/member-tank-projects/2838-samuels-new-huge-tank.html). Since it is kinda shallow, i am aesthetically limited to about 2 inches. In the sump, however, i will be doing all DSB using Amph's idea of the PVC supports to keep the LR off the sand.

Now, i gather that crushed coral (CC) doesn't really do much good at the best, and at worst is actually harmful. Any thoughts on this? It seems that CC would be easier to keep clean, relative to sand anyhow, since you could siphon it without sucking it all out of the tank.

Oh and one last question: i have heard that BB can sometimes cause erratic fish behavior in that they don't like seeing their reflection below. Has anyone experienced this, or am i misreading?

Seahorsedreams
11-16-2006, 05:49 PM
Isn't a 2" sandbed an intermediate sandbed? I've always heard

1" and less = shallow.
2 - 3" - intermediate (the danger zone).
and 3" is a DSB.

Although you would have to start out with more than 3" so that as sand dissolved you won't be thrown into the intermediate stage.

Reefbaby
11-17-2006, 06:56 AM
I think anything deeper than 4" would be considered a DSB....and yes, you're right Renee, you usually would want to start out a bit deeper since the sand layer does shrink over time.

Astrivian - I have a BB right now and I've never noticed any erratic behavior in my fish, and they were previously in a SSB of crushed coral. I haven't noticed any difference in them since removing the sand. The only fish that have really suffered were the gobies - hence my desire for a DSB with my new tank.

V
11-17-2006, 08:34 AM
the choices we make always govern the outcomes. http://www.alexander-oberg.de/smileys/viecher/heads_or_tails.gif

To be honest i would believe a remote bed would be far better than a dirrect bed, & least its semi pre filtered giving rise to less maintanence. I like BB for so many reasons. Sand adhesive Starboard has the look without the build-ups. Besides the practical applications substraites give an instant natral feel.

As for your fish RB, in some cases u find they will get spooked if they constantly see reflections on the glass floor or have problems percieving depth due to no definative floor.
my mangrove jacks dont mind in the slightest though!

V
11-17-2006, 08:43 AM
i need to change my vote, "who needs a sand bed, BB (bush boy) all the way babe"
http://www.alexander-oberg.de/smileys/viecher/sbdance.gifhttp://www.alexander-oberg.de/smileys/viecher/sbdance.gifhttp://www.alexander-oberg.de/smileys/viecher/sbdance.gifhttp://www.alexander-oberg.de/smileys/viecher/sbdance.gifhttp://www.alexander-oberg.de/smileys/viecher/sbdance.gifhttp://www.alexander-oberg.de/smileys/viecher/sbdance.gif

Seahorsedreams
11-17-2006, 01:53 PM
A remote DSB is suppose to be awesome, without the same risks of having it in your display tank. I do like some sand in there though because I LOVE Vibex..... they need their sand.

JustDavidP
11-17-2006, 02:02 PM
Um.. hey... lazy pants...

"Vibex"? I'm assuming you mean Nassarius Vibex? Not Cannophila vibex, a dragon fly, or Villosa Vibex, a freshwater mussle (Clam), or even the SS Vibex... http://www.merchant-navy.net/Images/thmb/tn_Vibex.jpg

an old British Merchant Ship? *giggle*

Dave

Seahorsedreams
11-17-2006, 02:36 PM
*throws a tomato*

I see you have Greg's verboseness and his sense of humour

gwen_o_lyn
11-18-2006, 08:29 PM
Now, i gather that crushed coral (CC) doesn't really do much good at the best, and at worst is actually harmful. Any thoughts on this? It seems that CC would be easier to keep clean, relative to sand anyhow, since you could siphon it without sucking it all out of the tank.

Oh and one last question: i have heard that BB can sometimes cause erratic fish behavior in that they don't like seeing their reflection below. Has anyone experienced this, or am i misreading?

I haven't seen my fish act any different with a BB tank.

As far as crushed coral, it has a larger surface area than sugar sized sand therefore resulting in more detritus being trapped. I recommend the small sized sand.

gwen_o_lyn
11-18-2006, 08:33 PM
Is there a voting option for one person using a barebotton, a DSB and a shallow SB? I'm using all three at the moment.

Renee - Welcome to the site!

I've updated the poll for you, so that option is now available. :)

V
11-18-2006, 09:12 PM
As far as crushed coral, it has a smaller surface area than sugar sized sand therefore resulting in more detritus being trapped. I recommend the small sized sand.

crushed coral has a larger diameter, although smaller grains occupying the same space has a greater surface ratio. Being the size of the grains, its the larger type that allow detritus to fall easier between the stuctures, i hear where your coming from, just the wording of the detritus bit shouldn't have flowing into the statement above it! ;)

gwen_o_lyn
11-18-2006, 09:23 PM
Thanks V- I was trying to say that but my grammar isn't so sharp.

Seahorsedreams
11-18-2006, 09:53 PM
Thanks for the welcome. I vote!

Crushed coral is not suppose to be used as a substitute for sand in a DSB.

V
11-19-2006, 06:24 AM
SHD, to be honest i like the look of a crushed coral bed better, esspecially texture wise, Its just a real shame so much crud builds up a hell of alot quicker, end result making the bactera that occupies it resiliant at best.
your right though, coral beds are not DSB's nor should they be regarded to have the same function. Although lets look at it from another nutral angle>
Bactera is still bactera, and it still populates promply & nicely. being that dead coral skells is more often than not more porus that sand some would say a small compromise.,& just as ethical in collection from rubble zones.
I still believe we place way to much importance on targeting certain media or practises when getting down to it your C.Alg encrusted glass & rockwork would be housing more than enough bacteraly speaking.

As always i love to go against the grain. Just the older & wiser*cough* im getting the less im getting caught in common thought that seems to have the hobby by the scruff of the neck. Non-conforming to tried & proven principles isn't really the flavour of the month anywhere.
Just in my eyes understanding your tank is more like the human body makes understanding the eco systems so much easier. Input in, transferance,Output out. Its only the compositions that change, if theres a shift in equalibrium nature accomidates without asking. As for systems all you have to do is provide the basic sustaining building blocks cause youv'e chosen to encapsulate it in a closed system.

*ouch, i twisted my ankle stepping off the soap box*http://www.alexander-oberg.de/smileys/zensurmann.gif