Dsb's work, what makes them work best?

[bertoni]

<a href=showthread.php?s=&postid=6474206#post6474206 target=_blank>Originally posted</a> by barryhc
IIs silica that harmful to the animals, and if so, are there alternatives, that are available down to .1 or .2mm?

Silica sand works quite well in practice, and can be better than the aragonite available for purchase. In Dr Shimek's course, the best DSB was silica, as measured by fauna.

I still don't care for the idea of "mud" and "flour-szed" substrate in the display, for reasons of clumping, PO4 release, and poor diffusion charachteristics.

Why do you think any of those are issues? We're not depending on diffusion in our sandbeds at that scale.

 

[bertoni]

<a href=showthread.php?s=&postid=6474398#post6474398 target=_blank>Originally posted</a> by aubee91
But IIRC, Dr. Ron says that the fauna on live rocks won't
populate the DSB anyway as they are not benthic. If so, seems like the critters on the live rock wouldn't be useful for DSB waste processing anyway.

I don't see any point in killing off interesting creatures for which I've paid good money. If you don't want them, dark-treat (cooking) is perhaps okay.

 

[Amphiprionocellaris]

<a href=showthread.php?s=&postid=6475925#post6475925 target=_blank>Originally posted</a> by KAiNE
Question..... wish i had asked this some time ago.

Since getting back into the hobby a few things have changed, sand being one of them. I ran BB from day one (other than a FO with CC and a UGF). In the late 80's to early 90's I never heard of sand beds and the thought of having sand in ones reef tank was unheard of, atleast to me. Now, in 05-06, all this talk about going back to BB...
Why did everyone seem to migrate to sand in the first place? the only reason i see is NO3 was there another reason?

There are lots of reasons. From what I've read, the sand beds pioneered by the likes of Jaubert were radical improvements in the husbandry of reefs. Primarily, they were more natural (and higher in biodiversity), and seemed to be less maintenance than their bare-bottom counterparts (I say "seemed" because I don't have first-hand experience with both). Then, as more people did DSB, and more couldn't get it to work (for various reasons), some gave up and went to bare-bottom (it was, after all, the first method to work). It is also worth noting, however, that both bare-bottom and sand bed methods have changed a lot since their first inception (as this thread suggests).

Of course, by the time I finish this post, someone else will have answered, but that's my look at it.

 

[bertoni]

<a href=showthread.php?s=&postid=6474678#post6474678 target=_blank>Originally posted</a> by aubee91
Okay, I'm unfamiliar with the difference between bioturbation and just frequent stirring. This bioturbation only occurs in the aerobic portion of the bed, right? So what is it about the bioturbation that increases the efficiency compared to frequent stirring by larger critters? Is it simply because there are so many of the smaller critters and they just turn the grains over more frequently on average?

Bioturbation is done by organisms. Ants and earthworms are great terrestrial examples. The process moves water and nutrients in and out of the sandbed. I don't know what you mean by "stirring", exactly, so I can't comment more.

Diffusion is worthless to move nutrients in and out of the sandbed because it's far too slow. Sandbeds do get some bulk flow that should help some, but without animals, the sandbed isn't going to function the same way. No processing of solid wastes as desired, etc.

 

[KAiNE]

<a href=showthread.php?s=&postid=6476033#post6476033 target=_blank>Originally posted</a> by barryhc
One of the reasons is for the animals that live in the sand, there are a lot of them. Another is aesthetics. Both apply to me.

NNR comes in third for me, but since I'm going to have sand for the first two reasons, I feel the need to do the best I can with the third.

> barryhc

I see....

So what has changed in BB that eliminated the issues we used to have? Dont say skimmers because we had em then, good ones too. The solution back in BC/BB was to starve the fish or have no fish at all. Now in AD/BB what is the solution to NO3, other than siphoning the bottom and WC (same as any method)?

As far as the aesthetics, i agree but i think a SSB looks better than a DSB but thats an opinion.

 

[bertoni]

<a href=showthread.php?s=&postid=6475177#post6475177 target=_blank>Originally posted</a> by aubee91
[B If so, it would seem to imply that Bomber is correct about the bed being a sink. Does an abundance of critters slow the "shallowing" of the interface? [/B]

There's no evidence or studies behind statements that a sandbed must turn into a sink, and there are counterexamples of beds that have lived a long time, by aquarium standards.

 

[barryhc]

<a href=showthread.php?s=&postid=6476063#post6476063 target=_blank>Originally posted</a> by bertoni
Silica sand works quite well in practice, and can be better than the aragonite available for purchase. In Dr Shimek's course, the best DSB was silica, as measured by fauna.

I'm glad to hear that.

Why do you think any of those are issues? We're not depending on diffusion in our sandbeds at that scale. [/B][/QUOTE]

We aren't?

At what scale?

If not then what is moving the nutrients and compounds, and what is the necessary function of the mud?

If the mud is not included, will it cause the sand bed to function improperly?

Some of the things I need to learn. > barryhc

 

[Weatherman]

<a href=showthread.php?s=&postid=6476105#post6476105 target=_blank>Originally posted</a> by KAiNE
I see....

So what has changed in BB that eliminated the issues we used to have? Dont say skimmers because we had em then, good ones too. The solution back in BC/BB was to starve the fish or have no fish at all. Now in AD/BB what is the solution to NO3, other than siphoning the bottom and WC (same as any method)?

As far as the aesthetics, i agree but i think a SSB looks better than a DSB but thats an opinion.

Loose rock structure and vigorous flow to keep organic particulates in suspension, and running skimmers real wet to get the particulates out as fast as possible.

It seems to work. A majority of BB people, in a recent poll, had no significant nitrates.

 

[Amphiprionocellaris]

<a href=showthread.php?s=&postid=6476105#post6476105 target=_blank>Originally posted</a> by KAiNE
So what has changed in BB that eliminated the issues we used to have? Dont say skimmers because we had em then, good ones too. The solution back in BC/BB was to starve the fish or have no fish at all. Now in AD/BB what is the solution to NO3, other than siphoning the bottom and WC (same as any method)?

I'm not quite sure on this, but my understanding is that the "new" BB method is to use extreme water flow to keep everything in suspension so that it can be removed (by skimmer, water change, etc.) before breaking down. That's just my understanding. Back on subject (sorta), it is worth saying again that the same principle (high water flow to prevent accumulation) can be used in all tanks, regardless of substrate.

 

[bertoni]

In practice, diffusion occurs and is needed, but I just can't understand how very fine, "flour"-like sediments could be a problem if used as a <b>part</b> of the mix. Perhaps I should have been more clear. I don't propose using only flour-level substrate, just as a part of the mix to get back to the ideal particle balance. The other Carib Sea products are all too coarse on their own.

 

[Amphiprionocellaris]

<a href=showthread.php?s=&postid=6476136#post6476136 target=_blank>Originally posted</a> by Weatherman
A majority of BB people, in a recent poll, had no significant nitrates.

Of course, as far as nitrates go, good LR should/will act as a denitrification zone. I believe there was an article in either Reefkeeping or Advanced Aquarist that detailed denitrification in LR.

 

[alten78]

its been an interesting thread to read to say the least. Alot of good opinions and theories on how things work and dont work, all while staying for the most part on track :thumbsup:

What I was waiting to read through all this was the actual day to day, weekly, or monthly maintenance and husbandry by those who havent had "problems" and those that have. The only thing I saw (unless I missed it) was not to stir it up or vacuum?

I kept a ssb (mainly for aesthetics and did not rely on critters) by blowing off and stiring on a weekly basis and have never seen cyano or hair algae in the tank *knocks on wood.* I will be moving to a 75 here in the next month or so and would really be interested in the actual procedures others have used as I am leaning towards dsb.

Thanks all!

~ba

 

[Weatherman]

<a href=showthread.php?s=&postid=6476185#post6476185 target=_blank>Originally posted</a> by Amphiprionocellaris
Of course, as far as nitrates go, good LR should/will act as a denitrification zone. I believe there was an article in either Reefkeeping or Advanced Aquarist that detailed denitrification in LR.

Very true.

And thatââ"šÂ¬Ã¢"žÂ¢s why the old-style Berlin tanks relied on a huge amount of live rock. The focus, then, was to perform denitrification in the tank. Didnââ"šÂ¬Ã¢"žÂ¢t always work very well.

The approach now is to get as much of that stuff out as possible before it breaks down.

 

[KAiNE]

<a Originally posted</a> by Weatherman
Loose rock structure and vigorous flow to keep organic particulates in suspension, and running skimmers real wet to get the particulates out as fast as possible.

It seems to work. A majority of BB people, in a recent poll, had no significant nitrates.

Other than the flow, this isn't new to me. I can see how higher flow will keep organics in suspension thereby allowing the skimmer to get it.
I am running a SSB (1" average, bare in the back). I also ran PVC under all my rock pushed via a Iwaki40RLT to prevent buildup in the low flow areas and to provide "pod" rich water to these areas. I also skim slightly wet and get roughly 1 gallon a day. I can definatly see how a DSB could go south for the reasons described in this thread but with either method or any combination there of, it boils down to import vs. export. If you're not exporting heavily, you will have problems no matter what method you use.

 

[barryhc]

<a href=showthread.php?s=&postid=6476136#post6476136 target=_blank>Originally posted</a> by Weatherman
Loose rock structure and vigorous flow to keep organic particulates in suspension, and running skimmers real wet to get the particulates out as fast as possible.

I think this is right, and these are huge pluses in almost any kind of system.

> barryhc

 

[barryhc]

<a href=showthread.php?s=&postid=6476171#post6476171 target=_blank>Originally posted</a> by bertoni
In practice, diffusion occurs and is needed, but I just can't understand how very fine, "flour"-like sediments could be a problem if used as a <b>part</b> of the mix. Perhaps I should have been more clear. I don't propose using only flour-level substrate, just as a part of the mix to get back to the ideal particle balance. The other Carib Sea products are all too coarse on their own.

Carib sea has Araganite at .1 to 1mm, and .1mm is within the range of "mud". Is there a reason why we "need" finer substrates than this in the tank?

Thanks > barryhc

 

[SDguy]

<a href=showthread.php?s=&postid=6476096#post6476096 target=_blank>Originally posted</a> by bertoni
Sandbeds do get some bulk flow that should help some, but without animals, the sandbed isn't going to function the same way. No processing of solid wastes as desired, etc.

Isn't this contrary to the idea of keeping flow high and particle size small to prevent actual particulates from entering the bed itself?

 

[joefish]

<a href=showthread.php?s=&postid=6473880#post6473880 target=_blank>Originally posted</a> by Amphiprionocellaris
I only partially agree. I wasn't talking about a tank-consuming bloom of algae; that is indeed a sign of a problem. I was talking about little blooms of algae; say, a little hair algae in a corner of the tank. It's a sign of phosphate, but the phosphate is locked up in the algae, rather than being in the water column where it can do harm (one principle of a refugium). Perhaps that phosphate came from waste that didn't make it into an area where it could be processed. All I'm saying is that algae (small blooms that affect aesthetics, not the big ones that kill stuff) shouldn't automatically be considered a sign of a bad DSB. Algae can be, and often is, a product of a bad sand bed, but not all algae comes from having a bad bed.

A sign of any algae should be treated as nutrients are building up . This doesn't mean a failed sand bed , it can mean many things . With a BB tank a bloom means you missed something and husbandry can make up for it . With a DSB , when do you know it's a bloom from cycling fauna or your husbandry skills need to be upgraded ?

When I use the term failed DSB , it means I kept upgrading my husbandry skills with no avail .

It's a sign of phosphate, but the phosphate is locked up in the algae, rather than being in the water column where it can do harm (one principle of a refugium). Perhaps that phosphate came from waste that didn't make it into an area where it could be processed.

Your not far off , but not right either . There will be some PO4 consumed and locked up by algae ( this is true) , but unless you find where the PO4 is starting , it will keep feeding the
free floating PO4 into the water .

Again if stony corals are being kept , the sight of most algaes should be used as a sign to correct something .



I also don't like the use of refugiums , but that's another thread .




PS; Reefers who have DSB working correctly , when you see algae starting to form , how do you know when it's just a fauna cycle or a sign of a bigger problem ?

 

[barryhc]

<a href=showthread.php?s=&postid=6476199#post6476199 target=_blank>Originally posted</a> by alten78
its been an interesting thread to read to say the least. Alot of good opinions and theories on how things work and dont work, all while staying for the most part on track :thumbsup:

Isn't it great !! :thumbsup: :thumbsup:

What I was waiting to read through all this was the actual day to day, weekly, or monthly maintenance and husbandry by those who havent had "problems" and those that have. The only thing I saw (unless I missed it) was not to stir it up or vacuum?

:thumbsup: :thumbsup:

You missed it partly. The general consensus is that up to 2" is certainly shallow, and stirring and vacuuming all the time is common practice. All the time? As much as you want. It is generally accepted that shallow sand is likely to be a Nitrate producer, but it can be handled.

> barryhc

 

[onthefly]

Originally posted by inwall75
You have to make a pretty big mistake to make aragonite turn into a brick.

Well plenty of people have done it....and in my case, no "big mistakes" were made. My only guess was the lack of sand movement and high flow (75x). Since the only section that was solid was the section in the highest flow. I had plenty critters, but lacked nassaraius snails or some other type of sand "mover".

For those interested in silica based sands......the major contaminating compound is feldspar (like weatherman posted). Get an MSDS on the composition of the sand and make sure it isn't there. I've built 2 silica based tanks with "quikrete medium grade commercial sand" from Lowes ($6 for 100lbs). Ivory white, southdown size grains, and the MSDS says 99.9% silica sand.