DSB controversy...spanning the boards.

[Anonymous]

"The DSB is exactly the same thing, but more surface area, more efficient.... "

Live rock has more surface area utilizeable to facultative anaerobes.

"do you have some convincing evidence that proves a DSB cannot handle the loads imposed on them when properly utilizing other export methods(such as skimmers, refugiums, carbon, etc)? "

Plain old ecology/biogeochem. Read the threads.


"wouldn't it seem likely that those systems using a DSB without the problematic algae would not be fitting to your sink analogy?"

They might not have filled up yet. I'm not saying good husbandry can't overcome the sinking. Len's systems are a perfect example.

 

[Anonymous]

Shane, try this: take 3/4" pipe, cap it, drill a 3/8" hole in the cap, stick it all the way down in the sample, plug the hole, and slowly pull it out...cap the open end as soon as it comes out of the sand. This is how we take microcores.

Only the top layer may (likely) not be representative of the detritus that has settled through the bed to the bottom.

 

[liquid]

Good idea. I'll give that a shot tonite. I'll go ahead and run this sample and then a full core just to see what kind of numbers we're talking about.

Shane

 

[Anonymous]

Awesome

 

[liquid]

You know, to be honest I'm suprised that no one on any of the other threads mentioned doing anything like this. Seems like a very simple starting out test. Now what would be *really* neat would be to figure out the chemical composition of the krud. That's something I can't do tho...

Shane

 

[liquid]

Galleon,

How did Sorokin, et.al. get around the problems of bacterial and microfauna contamination of their samples? You mentioned that Sorokin's numbers were 1% organic carbon, but that carbon could be worms, bacteria, etc. Any thoughts here?

Shane

 

[Len]

They might not have filled up yet. I'm not saying good husbandry can't overcome the sinking. Len's systems are a perfect example.

I'm not sure what "good husbandry" is. I admittedly am very lax with my maintainance. I don't do water changes anymore and I should've cleaned my skimmer 3 months ago My tank runs by itself with very little intervention on my part. I would think with my laid-back approach, my sandbed should've been "filled" long ago.

 

[ChrisRD]

Len. what types of creatures have you stocked to maintain the DSB? How often have you restocked your DSB with critters (if at all)?

 

[Anonymous]

Shane, my Sorokin book is at home. After work I'll take a close look a the text and his sources/methods. I'm curious about this too. I'm also going to try to find some lit on carbon percentages that are inclusive (ie, just strained stuff, as you are proposing).

 

[Len]

Chris,

I started with mostly dead aragonite and about 10% live sand. The sand and rock seeded the remainder of the sandbed, and I have never "recharged" it in 9 years. I'm not really keen on the effecitvness of recharging anyhow.

 

[sandworm]

I've have had shallow sand beds in previous tanks and most recently I set up a dsb of approximately 6" in my tank that has been going for six months. I added all the recommended lifeforms (worms, clams, etc.) when I set the dsb up. Eventually a crust formed on the top layer of sand that becomes covered in algea (cyno?). I worry that the crust will suffocate the lifeforms in the bed. Is this the standard cycle of a dsb?

 

[4angel]

Is this the standard cycle of a dsb?

More likely the standard of a new tank keep good water flow and it would eventually disapate. I am of the maintanence belife on the DSB issue syphoning and removing detritous where I can DSB 3" about 3 yrs now on a forty G. You have to go in there and get your elbows wet in this hobby.
_________________
Ferrari 512BB

 

[Anonymous]

"The DSB is exactly the same thing, but more surface area, more efficient.... "

Live rock has more surface area utilizeable to facultative anaerobes.

Chris- How do you figure? Sand has a huge surface area. A large percent of the rock is dry interior. And suitable anaerobic conditions are surely hit-or-miss at best.

 

[Anonymous]

"The DSB is exactly the same thing, but more surface area, more efficient.... "

Live rock has more surface area utilizeable to facultative anaerobes.

with all respect here, how can you state this? i would think that each (DSB and LR) would differ in capacity given the amount of it. and that rock would differ greatly in density meaning more or less efficient given the type. whereas the bed would differ in particle size and depth.

maybe you are saying that per pound on average LR has more? even then it would matter how deep and what size particle the sand is.



"do you have some convincing evidence that proves a DSB cannot handle the loads imposed on them when properly utilizing other export methods(such as skimmers, refugiums, carbon, etc)? "

Plain old ecology/biogeochem. Read the threads.

i have read them.
wouldn't this geometry work against the rock as well as for it? it seems the pitted areas would be more likely to trap more detritus thus need more energy released (as in accordance to Spankey's CACO2 theory) to relieve them.
i would also think there would be areas within the rock that would be every bit as cramped and bound as the sand bed and that these areas would be the primary anaerobic areas.
catch my drift?


"wouldn't it seem likely that those systems using a DSB without the problematic algae would not be fitting to your sink analogy?"

They might not have filled up yet. I'm not saying good husbandry can't overcome the sinking. Len's systems are a perfect example.

i see someone (Spanky again?) likened the effect to a septic system and that it would fill up at some point. i think this is an accurate analogy of what you and others are describing but this still doesn't take into account that there is export in our DSB systems that is lacking in a septic system.
SPC brought up a valonia tangent which sparked my attention. in the last couple years of my DSB i had valonia living below the upper surface of it along the glass viewing area. this leads me to speculation that the bed was functioning. it was breaking these organics down in a manner that didn't cause catastrophe.

i also am confused (as mojo predicted) as to what is so detrimental as far as inorganic detritus is concerned. you guys that worried about a sand bed?

 

[Anonymous]

sorry for the redundancy of the LR vs LS thing there

 

[sandworm]

If you run with the septic analogy, aren't septic systems set up to break down organics and isn't that what most of the recent literature and threads talks about with the thought that denitrifying bacteria do once they have established a large enough colony. A septic system uses bacteria to break down solid organics and then exports the broken down solids to leach lines. Perhaps the search should be for a different type of bacteria in dsb that are successful vs. those that crash.

 

[ChrisRD]

Not sure if it applies here, but a septic system will only break down the waste to a certain point. Eventually the system has to be cleaned (ie. pumped out).

 

[Anonymous]

Not sure if it applies here, but a septic system will only break down the waste to a certain point. Eventually the system has to be cleaned (ie. pumped out).

and that was the point over at TRT. it seems to fit the theory here.

my poiny is that a septic sytem may well never need be emptied if it had a skimmer on top or caulerpa being harvested from it.

 

[ChrisRD]

my poiny is that a septic sytem may well never need be emptied if it had a skimmer on top or caulerpa being harvested from it.

Well, as I indicated above, I have no idea to what extent the function of a septic system is really analogous to what goes on in a DSB (outside of the obvious bacterial treatment of wastes) - I'm not a marine biologist...

What I do know is that in a septic system the solids that settle out will only reduce/decompose to a certain point. I'm not sure I see how the protein skimmer or macro export example applies in this case as those are mechanisms that deal with nutrients in solution, not solid/particulate wastes.

 

[Anonymous]

my poiny is that a septic sytem may well never need be emptied if it had a skimmer on top or caulerpa being harvested from it.

Well, as I indicated above, I have no idea to what extent the function of a septic system is really analogous to what goes on in a DSB (outside of the obvious bacterial treatment of wastes) - I'm not a marine biologist...

What I do know is that in a septic system the solids that settle out will only reduce/decompose to a certain point. I'm not sure I see how the protein skimmer or macro export example applies in this case as those are mechanisms that deal with nutrients in solution, not solid/particulate wastes.

this wasn't only in response to you, Chris. i was just trying to add clarity to my own point.

that said, to you i now ask, why would the decomposition stop at any given point? all constituents are soluble in water, no? the difference with the added export that is available in our systems is it enables us to cleanse with water more readily.

i know that at least one of these reefkeepers that is describing his problems with the DSBs function wasn't using a skimmer and i didn't see he was using anything else either. i would guess that having water saturated with funk won't dissolve any funk. so this would result in a bed of funk.

also, i am willing to bet that if you ran enough clean water (no herbicides, etc.) through a semi full septic tank that you could successfully empty it of solids. it could take a good while but all will eventually dissolve or be consumed or possibly stay as an inert crust on the wall.