Dsb's work, what makes them work best?

[barryhc]

<a href=showthread.php?s=&postid=6466240#post6466240 target=_blank>Originally posted</a> by Sindjin
I think more research and emphasis needs to be focused on Phosphates in the DSB.

I quite agree.

Phosphates really dont get broken down...just pushed further into substrate... hence, like Bomber always said, that is why we have phosphate mines in Florida.

Not convinced at all of this one.

Yes, the DSB is a great addition to aid in denitrification but the storage of phosphates needs to be examined as I believe PO4 could be released slowly...causing algae blooms, etc.

This is the good part. This is quite true, especially the "could be" part. It has happened before in sand beds I'm quite sure, and has caused the crash, or failure, or whatvever. The big point here though is, IMHO, that it IS NOT a "necessary eventuality".

I'm asking because this aspect of DSB reef keeping really hasn't been answered...at least from what I have read, and I would love to learn more about it.

We are trying to answer it here, and it won't happen in a few days, but if you are really interested in reading, try the two terribly long posts of mine on this page, and then comment. Maybe the whole thread for that matter.

Let's see where it takes us.

Happy Reef Keeping! > barryhc

 

[Sindjin]

Also, wouldn't well cured live rock (some might say cooked) help with this aspect...much less detritus shedding from rocks = less buildup, if any in the DSB = less or no chance of "leeching" phosphates.

Yes, Cooked rock would help prevent shedding and adding unwanted waiste to your tank. I have a tone of flow in my BB but I still get one small area where a pile accumulates. Im fine with that. When I did that experiment, what I actually siphoned out was snail poop. And yes, I have observed the process so I know it was mostly snail poop. But in a DSB, you cannot always have as much flow as you want due to sand storms. I think periodic stirring is a good idea. I also believe that more DSB enthusiasts should look into Rock Cooking to allow the Rock to shed as much detritus out of it as possible before placing on top of a new sandbed. That way you are more in control of added waistes into the tank. This control, IMO is more important in a DSB than a BB.

 

[Sindjin]

BarryHC,

I read your "long winded" post and read a lot about denitrification....but not much mentioned on PO4.
I would also like to mention that I agree... that PO4 leeching in a DSB is not a "neccessary eventuality" like you mentioned. I think that most tank crashes, failures, etc are from poor husbandry or equipment failure. However after so many years of tiny bits of waiste accumulating somewhere in the sandbed...you cant help but wonder. Thats why I mentioned my experiment: to show that brand new snail poop tested at 3.0ppm. One day old, too. Imagine years of that accumulating and being stored in a DSB. Please understand that I am not bashing DSB's... merely thinking about it and wanting to learn!

I guess we need to get into the chemistry of PO4 and its relation to the N cycle to fully understand. I know there were some links to some published papers floating around here somewhere.

 

[barryhc]

<a href=showthread.php?s=&postid=6466376#post6466376 target=_blank>Originally posted</a> by SDguy
I'm not sure about that. Isn't the idea to have enough flow to keep the presumably lighter-than-sand detritus up off the sandbed? I know I have my flow set to shoot down then over the sand..set just right to not make an empty hole in the back of the bed, but still flowing out over the bed, then back up. (Granted, this is much easier to do in a hex tank I think, due to it's shape).

All right, you caught me!!! :lol: :lol: Yes it is very easy to get this high flow in a hex tank, especially with the rock work elevated by a couple of inches, like it is in mine. Both are very important considerations in almost any reef setup in my opinion.

I think that aquascaping has been the culprit as well in many applications, as it hinders flow, and unreasonably shields sand beds from proper processing.

Also, wouldn't well cured live rock (some might say cooked) help with this aspect...much less detritus shedding from rocks = less buildup, if any in the DSB = less or no chance of "leeching" phosphates.

What do you think?

Probably true to some degree, well almost certainly, but I'm not convinced that the mineral portion of detritus is that much of a burden in sand beds. Some yes, but probably very much less than the organic portion of detritus which is lighter and easily kept swept up into the water column for skimming etc..

 

[Amphiprionocellaris]

The problem with phosphate is that it doesn't have this nice, neat little cycle like nitrogen compounds, that result in N2 bubbling out of the aquarium. It can be changed into various forms, but it's always still there. Preventing detritus from breaking down is a major help, but I highly doubt that 100% prevention is possible (DSB or BB).
In a healthy DSB, the infauna should take care of the phosphates (or at least help) by consuming the waste that would release it into the water. It's like on the reef: there are tons (literally) of nutrients in the reef ecosystem, but they're used up faster than they're produced.
That might be why many DSBs experience an algae bloom after a couple of years: the infauna start to die off, leaving nothing to take care of phosphate. The process of extinction takes about 2 years, which seems to be the same time frame for "crashes" (though, again, I don't think the mere presence of algae means a crash).
Just an idea...

 

[barryhc]

<a href=showthread.php?s=&postid=6466779#post6466779 target=_blank>Originally posted</a> by Sindjin
I guess we need to get into the chemistry of PO4 and its relation to the N cycle to fully understand. I know there were some links to some published papers floating around here somewhere.

I think you are quite right about this, but information that is directly applicable to the processes inside our reef tanks is exceedingly difficult to come by, and even the few that exist, are often times deeply flawed.

We certainly don't need to reread any estuarial studies, or other hobby related studies that are biased toward or against certain methods. I have read oodles of those until I'm sick, and we need some fresh unbiased material to chew on.

There was a tremendous lot of information in those posts I suggested, that explain about potential sand storms and why they needn't be a problem. Did you catch that part?

Thanks for posting here Sindjin, let's see what we can learn.

> barryhc

 

[barryhc]

Another thing that I have been trying to get at, is that some of the "recipes" that have been followed to some degree, by most sand bed aquarists, have been promoted by people who believe that duplicating the "natural condition", is the best approach. I doubt that can be done even with 35 acres of water. "Duplication" simply isn't possible.

I do believe that mimicking the natural conditions to a degree THAT IS HELPFUL, is an excellent idea, while avoiding certain aspects of the natural approach, may be equally important, and I would include skimming as a valuable approximation of the natural approach, by the way.

I remain concerned about "muds" especially, and extremely fine sands, as potentially to likely "problematic" to use in the display tank itself, in most instances.

You can do whatever "floats your boat" in a refugium.

> barryhc

 

[SDguy]

<a href=showthread.php?s=&postid=6466790#post6466790 target=_blank>Originally posted</a> by barryhc
All right, you caught me!!! :lol: :lol: Yes it is very easy to get this high flow in a hex tank, especially with the rock work elevated by a couple of inches, like it is in mine. Both are very important considerations in almost any reef setup in my opinion.

Hehe, that's funny...I was actually referring to my own tank

 

[barryhc]

<a href=showthread.php?s=&postid=6467373#post6467373 target=_blank>Originally posted</a> by SDguy
Hehe, that's funny...I was actually referring to my own tank

Yeah but, what about those extra 3 gallons. I was thinking of upgrading to a thirty, but I'm concerned about the extra volume.

Here is a nice link on particle sizes, and "fauna". Thanks "Guy".

http://www.wetwebmedia.com/deepsandbeds.htm

It sounds like a special grade of .5 to 1.5mm would be optimum at the surface, for gobies, cucumbers, and other "sifter-burrowers"( and maintaining high flow and detritus rejection ). I wonder if it's available already, I'll check it out.

Happy Reef Keeping! > barryhc

 

[SDguy]

<a href=showthread.php?s=&postid=6467942#post6467942 target=_blank>Originally posted</a> by barryhc
Yeah but, what about those extra 3 gallons. I was thinking of upgrading to a thirty, but I'm concerned about the extra volume.

Here is a nice link on particle sizes, and "fauna". Thanks "Guy".

http://www.wetwebmedia.com/deepsandbeds.htm

It sounds like a special grade of .5 to 1.5mm would be optimum at the surface, for gobies, cucumbers, and other "sifter-burrowers"( and maintaining high flow and detritus rejection ). I wonder if it's available already, I'll check it out.

Happy Reef Keeping! > barryhc

Thanks for the link. This I find humerous too. I posted that link in another thread one time, for someone asking about sand depth/grain size. Someone else chimed in with something to the effect of "that article is murky at best"...though they left it at that with no relevent followup information.

 

[barryhc]

I expect it stayed very "murky" as well, considering all the "mud" that he insisted was necessary in order to run a sand bed "ala-Shimek".

I suppose my reference to to "recipes" is just about hilarious now that I notice his having referenced "mud" with the consistency of "flour" as the dominant factor in the "recipe".

I think I'm starting to have trouble breathing. When I crawl up off the floor and find the keyboard, I'LL LET YOU KNOW!!!!

Happy Reef Keeping!! > barryhc

 

[SDguy]

<a href=showthread.php?s=&postid=6468300#post6468300 target=_blank>Originally posted</a> by barryhc
I expect it stayed very "murky" as well, considering all the "mud" that he insisted was necessary in order to run a sand bed "ala-Shimek".

:eek2: :eek2: Easy there...I actually don't rememebr who chimed in to my post...it was no one that I knew.

Anyways, I've been trying to nail down any sort of trend when it comes to algal blooms and DSB. But people seem to get them 1, 2, 3, 5, never years later. Phosphate leeching can apply to all these scenarios? My head hurts thinking of the other factors one would have to look at....fish load, food introduction, flow, etc. Can we even come close??

 

[Sindjin]

barryhc,

I did read thru your posts referring to utilizing various substrates to avoid sandstorms. Perhaps more engineering is involved in the proper setup of a DSB....with various layer barriers, etc.

I read thru a bit of this thread . Dr Ron brought up some interesting points although some of it still seemed a bit biased. He mentioned that in an aquarium where there is a couple ppm of PO4, only a tiny percentage is actually bound to substrate. I could care less if the PO4 is bound to anything or not. All I know is that one day old snail poop emits a lot of PO4 (relative to the water column) and I want to remove it.... because so far, I dont know of any process that breaks it down. A while back, Bomber was mentioning something about bacteria utilizing PO4 during normal oxidation and denitrification processes... it was interesting...I'll try to look it up.

One final note... the aerobic and anaerobic processes that occur in a DSB also occurs inside our Live Rock so any factors we learn about PO4 in a DSB will also be very relevant to a BB.

See... we CAN all get along!


So whats everyone's take on Cooking Rock for a DSB? So far IMO, it seems to be more of a BB thing but I think it is even more vital for a DSB.

Phosphate leeching can apply to all these scenarios?

Yes, PO4 can cause all those scenarios.
PO4 will be instantaneously released into the water column with waiste excretment. Nitrates, however is a by-product of the ammonia released from that waiste.

 

[SDguy]

<a href=showthread.php?s=&postid=6468424#post6468424 target=_blank>Originally posted</a> by Sindjin
Yes, PO4 can cause all those scenarios.
PO4 will be instantaneously released into the water column with waiste excretment. Nitrates, however is a by-product of the ammonia released from that waiste.

Right, I understand all that. I was more getting at the idea that it will be nice, though difficult, to know why different DSB leech at different times. For example, is it even possible for accumulation to have occurred to such an extent in these situations where the algal bloom is in the first two years? Does this come back to properly curing live rock, and the DSB just ends up being the improperly cured live rock's scape goat??

So whats everyone's take on Cooking Rock for a DSB? So far IMO, it seems to be more of a BB thing but I think it is even more vital for a DSB.

I agree...though not to the point of cooking. Let's call it well cured

 

[Sindjin]

YES! Its all about the particular husbandry. If I set my tank up the way I read off of 3 different sites, I would have bought my live rock, put in my tank let it cycle for 2 or 3 weeks then removed it, put in 5" of sand and put the rock back in. Do you know how much crap my rock has spewed in the past 3 months? Tons... I couldnt imagine all that going into a new sandbed. No wonder so many experience algae blooms.

Thats why I believe in Cooking Rock...even though I didnt learn about this until after I set up my tank. All Rock Cooking is ....is Well Cured Live Rock that Cured in total darkness to kill off algaes.
Believe it or not, the process does not destroy all the life on the rock!

 

[barryhc]

<a href=showthread.php?s=&postid=6468335#post6468335 target=_blank>Originally posted</a> by SDguy

Anyways, I've been trying to nail down any sort of trend when it comes to algal blooms and DSB. But people seem to get them 1, 2, 3, 5, never years later. Phosphate leeching can apply to all these scenarios?

I don't see why not, since it would be a function of grain size, depth, flow, and most importantly feeding, mixed with the flow, and whether or not skimmng is being utilized, along with "how much bio-load". Most any time scale could apply, and aquarists have a tendency to try things out as well. Who's to say that the last "magic-bullet" didn't pan out, and the sand bed was to blame, rightly or wrongly?

Of course, algam blooms are not "strictly tied" to phosphate levels. Phosphate sure helps though.

My head hurts thinking of the other factors one would have to look at....fish load, food introduction, flow, etc. Can we even come close??

Sure we can, but is it going to happen next week or next month? That is what "they" thought 1,2,5,10,20 years ago. Was it true? then? Yes to some degree, but how close is close?

How about "closer"?

> barryhc

 

[Sindjin]

Every tank and every reef keeper is different, so many things are just NOT predictable due to many different variables.

 

[joefish]

<a href=showthread.php?s=&postid=6466386#post6466386 target=_blank>Originally posted</a> by Amphiprionocellaris
First, a thought about algae...
The presence of algae can't really be used (IMO) as a sign of DSB (or any system) failure. Algae is a natural part of the reef (as the zooxanthellae in your corals would tell you), and shouldn't really be considered a problem until it affects coral health (leaching, direct overgrowth, etc.). If it detracts from the appearance of the tank, it should be considered a nuisance, not a problem (very fine difference). There are, IMO, two primary reasons that algae does not totally dominate the natural reefs.

Algae is proof that all is not right . What does algae need to grow ?PO4 .

Now , If you don't mind seeing nuisance algae and the tank is geared twards soft Corals . Then you might be correct .

If you are geared more to Stony corals , they don't do well with PO4 present . SPS's realy does not like PO4 at all .

So nuisance algae is a sign of PO4 , and PO4 is bad . Then I would think that nuisance algae is a symtom of a worse problem .

 

[aubee91]

<a href=showthread.php?s=&postid=6468527#post6468527 target=_blank>Originally posted</a> by SDguy
Right, I understand all that. I was more getting at the idea that it will be nice, though difficult, to know why different DSB leech at different times. For example, is it even possible for accumulation to have occurred to such an extent in these situations where the algal bloom is in the first two years?

Is it possible that there are a couple of major mechanisms by which DSB's can work? It appears to me that DSB's as Dr. Ron wants them run are highly dependent on the infauna to work. I would assume that in this case (almost) all nitrates and phosphates are actually bound up in the bodies of the organisms living in the DSB themselves. I.e. worms eat snail poop and snails eat worm poop and smaller snails and worms eat their poop, etc. ad infinitum with the bacteria taking care of what little is left after all the critters get their share. In this case, not much denitrification would actually be occurring but rather nitrates (and phosphates) would be taken care of by the critters eating the nutrients.

In the case of a DSB that doesn't have a lot of infauna or critters, either because they weren't ever added or because they have died, denitrification by anaerobic bacteria is the main (or only) process occurring in the bed. And in this case the bed could or would work like Bomber and some others have proposed with the bed possibly eventually filing up and burping phosphate that has accumulated in the bed as a byproduct of bacterial denitrification.

Might this explain why some work and some don't and why some go for a long time and quit working while others quit working very soon? Feel free to dismiss this completely as I don't fully understand all the concepts and processes involved in this stuff. Which is why I'm reading this thread.

 

[barryhc]

<a href=showthread.php?s=&postid=6468424#post6468424 target=_blank>Originally posted</a> by Sindjin
barryhc,

I did read thru your posts referring to utilizing various substrates to avoid sandstorms. Perhaps more engineering is involved in the proper setup of a DSB....with various layer barriers, etc.

I read thru a bit of this thread

Firstly I won't have anything to do with Shimek, Sihiya, or Komoyo.

Secondly, yes, I think so, but I could be wrong. I kind of doubt it, but well see.

A while back, Bomber was mentioning something about bacteria utilizing PO4 during normal oxidation and denitrification processes... it was interesting...I'll try to look it up.

This is true, and it does get complicated, but reef tanks are complicated. Those who claim that they are not are either simple minded, or have an agenda. I don't tolerate either one very well.

One final note... the aerobic and anaerobic processes that occur in a DSB also occurs inside our Live Rock so any factors we learn about PO4 in a DSB will also be very relevant to a BB.

You Betcha!!!!

See... we CAN all get along!

Atta boy Sindjin!!!!!

So whats everyone's take on Cooking Rock for a DSB? So far IMO, it seems to be more of a BB thing but I think it is even more vital for a DSB.

I think that very many of the BB people are particularly into keeping SPS, and in some or even many cases, SPS are much more sensitive to Phophates than most other corals and animals.

They are driven to being obsessive, because some of the animals that they keep actually need the exceedingly nutrient poor conditions in order to survive. ( more so Phosphate, than Nitrate )

This apparently applies to nusiance algae as well, although I think it is really only a nusiance, and indicitave of nutrient levels, rather than actually detrimental to the corals.

Thanks again > barryhc