Dsb's work, what makes them work best?

[Acipenser]

I gotta ask this question. Why is important that the animals survive? Theoretically, aren't DSB's supposed to work by allowing denitrification to occur deep within the bed? Wouldn't it be okay to have a totally sterile aerobic layer (at least as far as infauna go) which gets stirred by stars, conchs, other large critters. At least theoretically shouldn't this work just fine? This is the idea behind the "DSB in a bucket" discussion from Anthony's forum, right?

I think there are two differing view points on this factor.

In my readings it seems that Calfo believes that in our reef systems our DSBs typically do not support the infaunal populations at levels that are necessary, based on our stocking the tank with creatures that eat the infauna. His use of a DSB in a bucket uses flow and mechanical filtration to prevent the accumulation of detritus in the sediment of the bucket, and uses the normal denitrification process of the bateria to reduce nitrates. More of a combined mechanical and bacterial approach.

Dr. Ron believes that DSB can be constructed to maintain sufficient populations of infauna. In this approach, detritus is processed by the various size creatures to eliminate as much nitrogenous waste as possible before bacterial processing. Then the normal denitrification process of the bateria in the sandbed is used to process the remainder. More of a biological and bacterialogical approach. Basically the fish poop is eaten by the snails, snail poop by the copepods, copepod poop by the etc... finally to bacterial conversion of ammonia to nitrate to nitrite to nitrogen gas.

Is either correct? I think that is determined on what you stock your tank with. I think each method will work effectively depending on the stocking conditions.

Thanks.

 

[inwall75]

<a href=showthread.php?s=&postid=6474986#post6474986 target=_blank>Originally posted</a> by kbmdale
Silica sand....Its funny when it comes to sand that the hobby veiws silica as BAD...But when it comes to tanks no one seems to care that the glass and seal is made of the same thing...

:lol:

"Reefer tales" seem to be much worse than "old wive's tales".

 

[kbmdale]

<a href=showthread.php?s=&postid=6475034#post6475034 target=_blank>Originally posted</a> by inwall75
:lol:

"Reefer tales" seem to be much worse than "old wive's tales".

"there once was a sand bed that stayed in a bucket, when the water got foul the old man decided to chuck it""


:lol:

 

[aubee91]

<a href=showthread.php?s=&postid=6474754#post6474754 target=_blank>Originally posted</a> by inwall75
Bioturbation is basically the mixing/turning over of sediments....what is typically called sand-stirring. It helps move water and it's wastes around. There are some critters who will go to the anaerobic portion of the bed but not many. Basically, the denitrification is NOT occurring in the anaerobic section of your sandbed...it is occurring at the anoxic interface. The more water you can get to this anoxic interface, the more efficient your bed is at denitrification.

Okay, that makes a lot of sense. The nutrients have to get to the bacteria that can convert them.

On a newer bed, this anoxic interface is much deeper than on an older bed. Other critters are quite helpful then. On an older bed, you might be fine with critters that don't go too deep. EDIT: But will it still work without them? Yes.

It this always the case that the interface gets shallower with age? 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?

 

[aubee91]

<a href=showthread.php?s=&postid=6475023#post6475023 target=_blank>Originally posted</a> by Acipenser
I think there are two differing view points on this factor.

In my readings it seems that Calfo believes that in our reef systems our DSBs typically do not support the infaunal populations at levels that are necessary, based on our stocking the tank with creatures that eat the infauna. His use of a DSB in a bucket uses flow and mechanical filtration to prevent the accumulation of detritus in the sediment of the bucket, and uses the normal denitrification process of the bateria to reduce nitrates. More of a combined mechanical and bacterial approach.

Dr. Ron believes that DSB can be constructed to maintain sufficient populations of infauna. In this approach, detritus is processed by the various size creatures to eliminate as much nitrogenous waste as possible before bacterial processing. Then the normal denitrification process of the bateria in the sandbed is used to process the remainder. More of a biological and bacterialogical approach. Basically the fish poop is eaten by the snails, snail poop by the copepods, copepod poop by the etc... finally to bacterial conversion of ammonia to nitrate to nitrite to nitrogen gas.

Is either correct? I think that is determined on what you stock your tank with. I think each method will work effectively depending on the stocking conditions.

Thanks.

Or maybe both are correct and both processes occur to different extents? In the case Anthony supports, the bed is acting mostly as a phosphate sink that will fill up and eventually need to be removed. Thus the putting it in an easily removable bucket. In the case Dr. Ron supports, the nutrients are (mostly) bound up in the bodies of the infauna and little sinking of phosphate occurs in the bacteria and/or bound to the grains of the substrate so the bed can operate indefinitely (or at least a potentially very long time) before failing. As long as the infauna survive.

The only drawbacks I can see to Dr. Ron's view is a) the cost of the kits to supply/resupply the infauna and b) not knowing whether/when this needs to be done. On the plus side, the DSB should at least act as a sink for a while even after an infaunal die off, right? If this is the case, could a bed that has a lot of stored phosphate in it be "rejuvenated" by adding critters? I.e. will they be able to "eat up" the phosphate that is sunk in the bed? Could a bed that is getting cyano growing on it and showing signs of imminent crash or failure be "fixed" just by adding critters?

 

[kbmdale]

Don't use the B word in this thread.... :lol:

 

[aubee91]

<a href=showthread.php?s=&postid=6475264#post6475264 target=_blank>Originally posted</a> by kbmdale
Don't use the B word in this thread.... :lol:

Bed? Bucket? Bacteria?

 

[kbmdale]

BOMBER!!!.... I don't trust people who disapear when thier credentials are questioned.

 

[aubee91]

<a href=showthread.php?s=&postid=6475336#post6475336 target=_blank>Originally posted</a> by kbmdale
BOMBER!!!....

I think we'll be all right if we all discuss folks' ideas based on the merit of those ideas rather than the credentials of those who espouse them. This thread is one of the few on RC in a long time that has been able to discuss these topics without a bunch of insults and closure. Let's try to keep it on track here.

 

[inwall75]

<a href=showthread.php?s=&postid=6475336#post6475336 target=_blank>Originally posted</a> by kbmdale
BOMBER!!!.... I don't trust people who disapear when thier credentials are questioned.

Kris,

Let's not go there. Bomber is gone by choice and that truly is his right. There's clearly more going on than anyone on this thread knows.

Let's just have the discussion and not have the thread closed.

 

[kbmdale]

I agree, there has been little arguement in this thread, but for every expert that claims a dsb will turn into a sink, there is one that says it doesn't. I just think the thread would be better off without the logic of the big B for once. His logic has always served one purpose .

Now I will say no more on that

 

[inwall75]

<a href=showthread.php?s=&postid=6475177#post6475177 target=_blank>Originally posted</a> by aubee91
It this always the case that the interface gets shallower with age? 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?

Actually, IMO, that's the point of this whole discussion. How do we make our beds more efficient. Improper construction, husbandry, etc. can result in a "failed" DSB pretty quickly. Partially correct construction, husbandry, etc. can result in a "failed" DSB over a longer period of time. How do we MAXIMIZE a DSB seems to be the point of the whole thread.

 

[inwall75]

<a href=showthread.php?s=&postid=6475023#post6475023 target=_blank>Originally posted</a> by Acipenser
I think there are two differing view points on this factor.

In my readings it seems that Calfo believes that in our reef systems our DSBs typically do not support the infaunal populations at levels that are necessary, based on our stocking the tank with creatures that eat the infauna. His use of a DSB in a bucket uses flow and mechanical filtration to prevent the accumulation of detritus in the sediment of the bucket, and uses the normal denitrification process of the bateria to reduce nitrates. More of a combined mechanical and bacterial approach.

Dr. Ron believes that DSB can be constructed to maintain sufficient populations of infauna. In this approach, detritus is processed by the various size creatures to eliminate as much nitrogenous waste as possible before bacterial processing. Then the normal denitrification process of the bateria in the sandbed is used to process the remainder. More of a biological and bacterialogical approach. Basically the fish poop is eaten by the snails, snail poop by the copepods, copepod poop by the etc... finally to bacterial conversion of ammonia to nitrate to nitrite to nitrogen gas.

Is either correct? I think that is determined on what you stock your tank with. I think each method will work effectively depending on the stocking conditions.

Thanks.

I was busy typing or was on the phone. This is a post worth reading and discussing IMO.

 

[barryhc]

Yeah buddy!!!!!!!!!

quote:
--------------------------------------------------------------------------------
Originally posted by Acipenser
I think there are two differing view points on this factor.

In my readings it seems that Calfo believes that in our reef systems our DSBs typically do not support the infaunal populations at levels that are necessary, based on our stocking the tank with creatures that eat the infauna. His use of a DSB in a bucket uses flow and mechanical filtration to prevent the accumulation of detritus in the sediment of the bucket, and uses the normal denitrification process of the bateria to reduce nitrates. More of a combined mechanical and bacterial approach.

Dr. Ron believes that DSB can be constructed to maintain sufficient populations of infauna. In this approach, detritus is processed by the various size creatures to eliminate as much nitrogenous waste as possible before bacterial processing. Then the normal denitrification process of the bateria in the sandbed is used to process the remainder. More of a biological and bacterialogical approach. Basically the fish poop is eaten by the snails, snail poop by the copepods, copepod poop by the etc... finally to bacterial conversion of ammonia to nitrate to nitrite to nitrogen gas.

Is either correct? I think that is determined on what you stock your tank with. I think each method will work effectively depending on the stocking conditions.

Thanks.
--------------------------------------------------------------------------------

<a href=showthread.php?s=&postid=6475263#post6475263 target=_blank>Originally posted</a> by aubee91
Or maybe both are correct and both processes occur to different extents? In the case Anthony supports, the bed is acting mostly as a phosphate sink that will fill up and eventually need to be removed. Thus the putting it in an easily removable bucket. In the case Dr. Ron supports, the nutrients are (mostly) bound up in the bodies of the infauna and little sinking of phosphate occurs in the bacteria and/or bound to the grains of the substrate so the bed can operate indefinitely (or at least a potentially very long time) before failing. As long as the infauna survive.

The only drawbacks I can see to Dr. Ron's view is a) the cost of the kits to supply/resupply the infauna and b) not knowing whether/when this needs to be done. On the plus side, the DSB should at least act as a sink for a while even after an infaunal die off, right? If this is the case, could a bed that has a lot of stored phosphate in it be "rejuvenated" by adding critters? I.e. will they be able to "eat up" the phosphate that is sunk in the bed? Could a bed that is getting cyano growing on it and showing signs of imminent crash or failure be "fixed" just by adding critters?

I think were really starting to get somewhere now. We don't seem to quite have the answers here yet, although I basicly agree with both of the posts above.

We sure have zeroed in on one very large question though, and I think that the learning that we get on this issue will have far reaching implications on all reef keeping issues, like RDSB, and refugium, and reactors, and . . . . .

Thanks to everyone for getting us here, and being so nice about it along the way!!!!

Happy Reef Keeping ! > barryhc

 

[Amphiprionocellaris]

originally posted by aubee91
Or maybe both are correct and both processes occur to different extents? In the case Anthony supports, the bed is acting mostly as a phosphate sink that will fill up and eventually need to be removed. Thus the putting it in an easily removable bucket. In the case Dr. Ron supports, the nutrients are (mostly) bound up in the bodies of the infauna and little sinking of phosphate occurs in the bacteria and/or bound to the grains of the substrate so the bed can operate indefinitely (or at least a potentially very long time) before failing. As long as the infauna survive.

The only drawbacks I can see to Dr. Ron's view is a) the cost of the kits to supply/resupply the infauna and b) not knowing whether/when this needs to be done. On the plus side, the DSB should at least act as a sink for a while even after an infaunal die off, right? If this is the case, could a bed that has a lot of stored phosphate in it be "rejuvenated" by adding critters? I.e. will they be able to "eat up" the phosphate that is sunk in the bed? Could a bed that is getting cyano growing on it and showing signs of imminent crash or failure be "fixed" just by adding critters?

First, two comments on the bucket method
1) Getting nutrients from the tank to the bucket could be very difficult. However, good turnover and a little engineering should circumvent that aspect.
2) Restarting a sand bed upon removal of the old one could be problematic (going through a new cycle). It is possible (if not likely), though, that the denitrators in the live rock could pick up the slack until the new bed is established. Or, perhaps, one could use a staggered pair of buckets, so that you always have a good bed on the system, even when replacing. Sort of like staggering the lights on a tank so that only half of them are old.

There's also the concern that not all the phosphate will get into the bucket, but the phosphate left should be marginal enough that it doesn't matter. There's also the problem of knowing when the bucket is ready to be switched out.

I'm not trying to knock anyone's method. I'm just pointing out potential problems so that they can be fixed (as per the goal of this thread). A little experimentation should provide the necessary information for both methods (eg. when the bucket is saturated and questions about restoring fauna), and I'm going to be in a position for some heavy research starting next semester.

 

[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?

 

[bertoni]

<a href=showthread.php?s=&postid=6473310#post6473310 target=_blank>Originally posted</a> by Acipenser
Bertoni,



Care to elaborate? PM me if necessary.

Seems to me that they have a lot of information on the subject and to flatly reject their ideas seems a little irresponsible for this thread.

I didn't write the quote you posted.

 

[Weatherman]

<a href=showthread.php?s=&postid=6475925#post6475925 target=_blank>Originally posted</a> by KAiNE
Why did everyone seem to migrate to sand in the first place? the only reason i see is NO3 was there another reason?

That's all.

And, it looks pretty.

 

[bertoni]

<a href=showthread.php?s=&postid=6473179#post6473179 target=_blank>Originally posted</a> by Sindjin
Thats just it... to me COOKING (dark curing) is even more essential in a DSB than a BB. It kills off all the algaes and allows bacteria from inside the rock to expell all the PO4. The critters you speak off to process waiste is the bacteria. Cooking the rock does NOT kill off this bacteria... nor does it kill all the "life" on the rock. Rocks will shed. The problem is we can't determine how much because we dont know what is actually built up inside it. Thas why to me it is vital for a DSB to have Rock that is a clean as possible.

I think this is all wrong, but I don't want yet another rock cooking thread, so I'm not going to debate. I would request that the rock cooking debate be taken elsewhere. It seems we both agree that it's not specific to DSBs.

 

[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