Limitations of DSB's

[aquaticsdeptleader]

one more thought lots of surface area on rock tank has maximum amount of live rock space and still have water i still want more surface area got a whole bare bottom here might as well use it for something?

jim

[cyberchef]

I agree Jim...

Like I said, I'm not getting rid of my plenum, it's been working too well for me to just chuck it. But I also feed very light prefering for my refugium to produce fodder for the tank.

[galleon]

"Unfortunately I've been out of chemistry long enough that the "Hint: think phosphorous" missed me... "

Bacterial action converting organic phosphates to leached orthophosphates. Algae utilizing orthophosphates and leaching pooling organic phosphates. Bacterial action converting organic phosphates to leached orthophosphates. Algae utilizing orthophosphates and leaching pooling organic phosphates. Positively vicious .

[Spanky]

Originally posted by galleon
"Unfortunately I've been out of chemistry long enough that the "Hint: think phosphorous" missed me... "

Bacterial action converting organic phosphates to leached orthophosphates. Algae utilizing orthophosphates and leaching pooling organic phosphates. Bacterial action converting organic phosphates to leached orthophosphates. Algae utilizing orthophosphates and leaching pooling organic phosphates. Positively vicious .

ROTFL

again right on the money. And when the sponge fills up, this is exactly what you get.

[Geoff]

ok, how often is the sea floor regenerated? due to plate techtonics the sea floor is constantly being created and destroyed. would this not be the same as replacing parts of our DSB? would this be one of the ways the ocean gets rid of its end detritus?

Jerel-i must be brain damaged here, i can not see how a rock with X volume, can have more surface area than the same X volume of fine sand. the rocks we use in our closed systems are generally very porous. there is a lot of water volume in these rocks.

if the areas of maximum surface area are the end detritus sinks. and we should be removing this end detritus after X period of time. then i would rather remove the sand than the LR. but if the LR has more surface area to trap the end detritus then we are all in for an expensive undertaking every X period of time.

Also, would the LR we are putting in our closed systems already have a lot of end detritus in them from the places they were collected from?

once again, i guess it all can be broken down to the concentration game!

G~

[SPC]

Originally posted by cyberchef
Also, ever since I started getting into"reefs", I've been striving to "develop" a self sustaining ecosystem. my whole reason for using refugiums in the first place. I don't use them for nutrient export, but for nutrient import instead in the form of the production of live food.

Great topic.
Cyberchef, this "self sustaining ecosystem" concept seems to me to be at odds with being able to remove organic compounds before they have a chance to build up.
Steve

[tdwyatt]

Hmmmm...

Fortunately I am at a crossroads that will allow me to try a different approach to the entire concept presented here. I will be setting up 2 identical 125 gal systems with one small difference: one will have the "settling tank" for detritis and remote dual sandbeds, possibly a thin sandbed or a bare bottom in the actual display: and the other will be a 6 inch DSB tank with a 6 inch dsb substrate refugium. These will definitely be closed systems, using totally ASW , most likely IO. I will be installing sampling cannula at different depths in the DSB-equipped tank. Both will have similar populations and biome setups, and I will attempt to make them both as close to identical as possible with the exception of how the sandbeds are run. The idea of using the dual remote sandbeds will be to have the opportunity of changing one sandbed out completely (yeah, Southdown...) at say 2 or 3 years from day 1, then once the new sandbed has matured, to change the other out at say 5 or 6 years. Each sandbed will have sufficient capacity and volume by itself to handle the bioload of a coral system at 125 gal capacity. It will be just one example, but it will be hopefully one of many systems set up in such a manner across the country. Heh!, the 180 will still be set up with a DSB and refugium as they are now, but the sand bed will be totally new. I also intend to test the old sand samples for content re: heavy metals, organic/inorganic phosphate, etc. as this sand bed is about 5.5 years old. I will post whatever results I get with the DSB tests from this teardown.

Any suggestions?

Much to consider...

[cyberchef]

Originally posted by SPC
Great topic.
Cyberchef, this "self sustaining ecosystem" concept seems to me to be at odds with being able to remove organic compounds before they have a chance to build up.
Steve

First off, unless I feel there is a reason to do so, I don't run a skimmer. Yes I do understand the discussion were having and I'm even contributing to it in the sense of helping to point out the problems with a DSB. But as has already been pointed out, one of the biggest contributors to the "problem" is from the addition of supplements and processed foods to our closed systems. I'll bet between this and other boards, I've seen more problems with aquaria due to skewed water parameters, due to the uncontrolled/untested use of additives and because of overfeeding, than I have for any other reason.

I stopped using additives other than calcium and buffer almost a year ago, and have been only using Kalk for the past 4-5 months. Part of the reason for this was that I was having problems that could not readily be explained. I stopped using additives, did a few major water changes and suddenly the tank settled down and the problems disappeared. I stopped using seperate calcium and buffers because I was having too much trouble keeping the calcium and Alk stable, I started dripping Kalk and now they stay stable (although I will occasionally give the calciuma boost with a dose of turbo calcium).

A lot of the organic compounds we need to remove are there because we add them in the form of additives and processed foods (ie: flakes, blendermush, frozen foods and a meriad of other "good" things for our fishies and corals).

Originally posted by dark horge

Let's just talk metals, since that is the gremlin being conjured up.

It's ironic (Fe being one of the few metals tolerated) that all this attention is being focused on contaminant metals in salt mixes, when the primary source for excess metals is food imports.
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DSB's, if I recall, are meant to allow the operation of high-energy foodwebs. I will agree with Ron that DSB's take a serious whack at niitrogenous waste --I've said so here before. But if a DSB-based system can't handle the accumulation of metals, then what's the point? Your system is still headed for a crash.
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Unless you can mimic the export function of water currents, you will have a very hard time sustaining a system free of surplus metals (toxic, limiting or whichever) in the context of a high energy foodweb. This means inducing better water movement than a "do not disturb" DSB would allow.

If you're not into heavy feeding, why bother with a DSB?
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Besides, if we want to get into heavy feeding, I think we'd be better served by efforts to refine refugium (and I mean true refugia, not these algal 'eco' systems being hawked,) productivity, and minimize dead-food imports. People seem constrained by the inexplicable assumption that a fuge OUGHT to be only so big... but I digress.

While Horge did "confine" his post to metals, since the original "gremlin" was metals, I think you'll find that what he had to say about "food imports" will also apply to additives and that they are the major contributor of the majority of organic compounds we try so hard to remove from our systems. Natural live foods don't become "organic compounds" that need to be removed until they are consumed and processed into detritous or if they die and decompose. But these natural live foods are not going to import any unnatural or excessive organic compounds into our closed loop ecosystems. They thrive and reproduce by utilizing what already exists in the ecosystem and when they are comsumed they can only add back what they originally took in, not something that they got from a bottle or can.

Does this mean we can set up a closed loop ecosystem and never have to worry. NO... We still have to use good husbandry techniques, test water parameters and do water changes. We will never be able to "perfect" a totally perfect cloed loop ecosystem, just the smallness of our systems will prevent it. We will never be able to sustain all of the organisms needed to accomplish this, there are just too many natural variables that we cannot successfully reproduce. Of course, the larger your system is and the larger the refugium, the better chance you have of coming close because your system will be able to sustain a much larger and diverse bethnic population. But again, without the currents, storms and such produced by nature there is still no way for us to effectively remove all of the waste from our systems in the same effective manner that nature can accomplish. But if we use a natural method of feeding, that utilizes what already exists in the system, then we can effectively/greatly reduce the amounts of excess organics that are found in the majority of these closed systems, because we are not adding all of the excess.

If you were to take a bottle of water and close it up, one year from now you open the container and the only thing in the container is the water you originally added. Add 1 piece of shrimp, close the bottle back up. Another year passes and you open the bottle back up. Inside you will find water that also contains all of the organic compounds produced by the decomposed shrimp. But you will not find tons of other organic compounds that did not exist in the shrimp. Basically all you will find in the bottle (closed ecosytem) is anything that you have added to it.

[SPC]

Maybe I am not following exactly the kind of system you are striving for here Cyberchef.
The only thing I add to my tank is kalk and blender mush. If I take the skimmer off line, will i have the same system as you, or do you not feed at all? And if you do feed, how do you guage how much organics and heavy metals are left over as the end product?
One more question if you don't mind. If I take a fresh shrimp and feed it to my animals, and they eat every bit of it, how is this different than them eating something live in my tank? It would seem to me that this live food in our tanks would also be putting off waste that my dead shrimp would not.
Steve

[mojoreef]

Ok I would like a little more detail on how all detritus is not processed in a DSB. Maybe a link or 2 on a study even,


Mike

[mojoreef]

Oh yea and I would like to know what end product detritus is. and why is it.

Mike

[cyberchef]

Originally posted by SPC
Maybe I am not following exactly the kind of system you are striving for here Cyberchef.
The only thing I add to my tank is kalk and blender mush. If I take the skimmer off line, will i have the same system as you, or do you not feed at all? And if you do feed, how do you guage how much organics and heavy metals are left over as the end product?

I feed extremely light (once every 7-10 days), for one thing I only have 3 fish and the refugium supplies food for at least one of them. I've had all of my fish for over 8 months, they have all grown since I got them and they are definately not starving.

I know nothing about your system so I can't really answer that question. I have a 55 RR main with 3 other tanks plumbed into the same system. My sump has a built in skimmer (which rarely gets used) and I've removed the "bio bale" and replaced it with large pieces of LR. The other three tanks are 1 refugium and 2 frag/grow out tanks. My main tanks has approximately 125# of LR (mostly gulf aquacultured), DSB (5" approx) with a plenum under that. I've purposely set up the refugium to produce "food", in the form of pods, baby shrimp and any other young that are produced (basically it produces planktonic life for the tank), to feed the tank. I have a lot of SPS corals as well as a few softies and 2 clams (1 squamosa, 1 derasa). All of which are healthy and growing nicely. Before we moved my tanks were all crawling with all sorts of pods, grammaris shrimp, mysis shrimp,various worms... etc. As with anytime you move a system (I also added 2 of the three "other" tanks at this time and lost a second refugium to a broken pane of glass), I did experience a small cycle, but the tank is recovering nicely and my pod population is getting back up to snuff. Before the move, I had 2 refugiums at that time, both of the refugiums looked like NY city at rush hour there were so many pods running/swimming around (lights on or off).

I do test parameters on a fairly regular basis, especially while the tank was reastablishing itself after the move. I don't even try to guage heavy metals as I don't have nor can afford the equipment it would take to monitor it. I watch the Macros in the refugium as well as watch the rest of the system to guage if there is a problem. If there is an excess of organics, tests will show nitrates or ammonia and the macros will grow faster as well as my xenia will also grow faster and spread.

One more question if you don't mind. If I take a fresh shrimp and feed it to my animals,

You have to ADD the "fresh" dead shrimp to your tank/system in order for your fish to be able to eat it... It was not already there in any way, shape or form.

and they eat every bit of it, how is this different than them eating something live in my tank?

After they eat the "fresh" dead shrimp that you have added to your tank they will excrete detritous (at some point). This detritous is added additional waste that has never ever, in any way, shape or form, been in your system.

The "live" food produced by pods/critters are derived from the "parents" eating things that already exist in your system (ie: macro algaes, other infauna and the waste produced by the "fish and coral" eating the previous batch of offspring). The waste produced by the corals and fish from eating the planktonic life forms, already existed in the closed loop system in some way,shape and form (ie: algaes, waste, planktonic life.. etc). And therefor does not add any additional organics to the closed loop system, these organics already existed in some way, shape and form.

It would seem to me that this live food in our tanks would also be putting off waste that my dead shrimp would not.
Steve

They are putting out waste, all creatures that ingest nutrients also realease nutrients in some form. But, again, these nutrients that they are releasing already existed in the closed loop system in some way, shape or form. These nutrients are just getting recycled over and over again. They are not adding any new additional organics/nutrients to the closed loop system.


Nutrients in the SB and water column (detrituous) ======> algaes,planktonic life and micro/macro fauna ========> pods, critters and thier offspring ====> fish and corals ====> detritous ===> nutrients in the SB and water column

[cyberchef]

Originally posted by mojoreef
Ok I would like a little more detail on how all detritus is not processed in a DSB. Maybe a link or 2 on a study even,


Mike

Mike it is all processed at some level but it still never goes away. Just gets recycled or in the case of toxic metals, burried in the DSB, tied up in the dead bodies of long gone bacteria..


Sorry I refuse to post a study that is not valid or that I have not actually performed...

[cyberchef]

Originally posted by mojoreef
Oh yea and I would like to know what end product detritus is. and why is it.

Mike

Sorry detrituous is not a final end product. Just the end product of consumption, kinda like when you eat too many tacos washed down with beer. The tacos come back out in a hurry, just not in the same form as they went in..

[mojoreef]

Well DOn thats not what I am hearing here. And you know me I love being the devils advocate.
The common idea that has been pushed by some not to be mentioned expert is that all detritus is processed inot some form of a gasious state, ie sulphide or N. Now we are being told that is isnt and that actually thier are alot of stuff left behind, one being end product detritus. So my questions stands what EXACTLY is being left behind and what does end product detritus consist of. Iwould also like to see some studies and or articles that show this. I want bullets people not daisys, lol

mike