Cryptic Zone Filtration

[mr.wilson]

Regardless of what others' think, the addition of a few sq. ft. of unlit space either by means of a garbage can or blacked-out aquarium requires little effort or space.

Another under-appreciated and overlooked method is the addition of more water volume. If you have a 200 gallon display, surely adding a 500 gallon reservoir in the basement or garage makes a big difference in nutrient concentration and temperature control. A $300 reservoir from a farm supply store is a lot cheaper than electrical gear and chemical media. Water changes are spread out more and much safer to execute.

... and by all means, throw some rock or eggcrate in the reservoir for your friends

 

[tmz]

I think the fundamental difference is one will process nitrogenous waste (DSB).

As will additional rock surfaces or a shallow bed , perhaps even better if the dsb is not getting adequate flow in the depths.
The bacteria that perform denitrification are faculative( they use O2 and when it's exhausted ,they use the O form NO3 and consume some of teh N and/or convert it to N which then forms N2 nitrogen gas). They are also heterotrophic( they do not make their own sugars ; organic carbon) . They need a supply of organic carbon, nitrogen and phosphorous to live and grow. They can denitrify in very shallow areas even in the bacterial mulm .
DSBs have benefits and flaws and may be very inefficient and even toxic with hydrogen sulfide, for example , when not reseeded with critters to keep nutrients and nitrate moving and to keep channels open and unclogged to prevent anoxia. They provide lots of surface area for colonization in a small space but they are not necessary for denitrification. A cryptic zone can support these facultative heterotrophs too.

 

[DeathWish302]

I think the fundamental difference is one will process nitrogenous waste (DSB).

As will additional rock surfaces or a shallow bed , perhaps even better if the dsb is not getting adequate flow in the depths.

Tom,

I had one of those moments of 'DOH' after I read my prior statement. I agree that cryptic/benthic zones process nitrogenous waste in the same manner as a DSB. What I meant to say (and poorly executed the wording of that thought...:headwalls was that both systems likely generate large blooms of zooplankton, but the majority of persons believe that only one will process nitrogenous waste.

I've read several articles by Bornemann and Shimek over the years that did state that even a 1/4" of sediment can be an adequate surface to reduce/eliminate NO3. So I too agree that given enough surface in a cryptic zone, one could have the same effectiveness as a DSB if your only goal is NO3 reduction. I do agree it you have problems with detritus build-up, the cryptic zone may also be the best option.

Sorry if I came off half-cocked before, but I guess I need to read into my statements more to see all angles.

 

[tmz]

The fact that many people think only a dsb with undisturbed anaerobic zones processes NO3 illustrates the fact that the way denitrifying bacteria live and work is largely misunderstood particularly in the deep sand bed discourse.
I needed to clarify that.
I agree that a cryptic set up is very low maintenance with virtually no operating costs. Mine don't even need pumps as they are fed by drain lines .

The additional water volume is a plus too .imo.

FWIW I use an unlit dsb piled with live rock to enhance advective flow into the sand as well.

 

[elegance coral]

I agree! BUT...even Ron makes the remark he 'recharges' his DSB infauna bi-annually.

Yep.... That could be viewed as a fundamental difference. It is a difference that would tip the scale in favor of Tyree though. Not Shemik and Borneman.

I think the fundamental difference is one will process nitrogenous waste (DSB).

I wasn't referring to microbes. I'm asking about higher organisms like sponges, tunicates, worms, and pods.

 

[elegance coral]

Adequate bacterial colonies alone can maintain Po4 and No3 at zero,

How do bacterial colonies alone maintain phosphate at zero? In a mature and stable system, how can they reduce phosphate at all?

 

[elegance coral]

Okay...... Maybe I'm not wording this right.
Greenbean said this when referring to Tyree.
"He makes unsubstantiated and often ridiculous claims about these animals and their potential benefit to a reef tank."
The same exact thing can be said about Shemik and Borneman when they talk about the inverts in their DSB. How can you embrace one, and dismiss the other, when they both rely on inverts eating small particles?????? Hopefully Greenbean will chime in and clarify how this is possible.

 

[tmz]

I'm not sure in Shimek's deep sandbeds it's a matter of critters processing inorganic PO4 and NO3 as much as it is burrowing and cleaning the sand bed to allow flow and pooping some organics to support anaerobic bacterial activity.

The cryptic zone discourse,unfortunately, includes largely unsubstantiated claims of certain macrofauna(sponges, tunicates ,polychaetes,etc) vaguely processing inorganic forms of nitrogen and phosphorous and dissolved organic carbon and toxins as benefits that appear dubous to me.

In my view bacteria do most of the processing of the NO3 and PO4 in both systems.

It's easier to keep an adequate flow of the inorganic P and N and organic C in a dark rock pile than it is a deep sand bed ,ime.

 

[mr.wilson]

How do bacterial colonies alone maintain phosphate at zero? In a mature and stable system, how can they reduce phosphate at all?

Bacteria remove carbon, nitrogen, and phosphate in that order. In most cases some residual phosphate will be left over once the C & N is gone. GFO, LC or a refugium may be required to get absolute zero but not necessarily.

 

[mr.wilson]

Okay...... Maybe I'm not wording this right.
Greenbean said this when referring to Tyree.
"He makes unsubstantiated and often ridiculous claims about these animals and their potential benefit to a reef tank."
The same exact thing can be said about Shemik and Borneman when they talk about the inverts in their DSB. How can you embrace one, and dismiss the other, when they both rely on inverts eating small particles?????? Hopefully Greenbean will chime in and clarify how this is possible.

I don't believe Greenbean embraces the theories of Shimek, Borneman or Tyree so there is no double standard.

 

[elegance coral]

Bacteria remove carbon, nitrogen, and phosphate in that order. In most cases some residual phosphate will be left over once the C & N is gone. GFO, LC or a refugium may be required to get absolute zero but not necessarily.

Carbon and nitrogen can be removed from the system through gas exchange. How do bacteria remove phosphate?

 

[tmz]

Bacteria don't remove phospahte ,per se ;they consume it giving it an organic form.Bacteria and some other organics they produce are exportable via skimming or gac and take C. N and P with them.The inorganic phosphate( PO4 species) are also removable via adsorbtion by binders like gfo or alumina , possibly skimmable as precipitant and harvestable as a macroalgae ,turf algae or nuisance algae. .

 

[DeathWish302]

So, it's been 3 months and I have seen an explosion of calcareous tube worms, cirratulid worms and aiptasia. The eggcrate that was placed int he cryptic zone seems barren and only the glass and 5lbs of LR has life on it.

I would say for the most part I am happy with my cryptic bacteria factory.

Now the bad.......:uhoh2:

I've accumulated about 1/8" of detritus and have tried continual purges with basting and increasing the flwo from the trickle the tank was receiving. I;m about to the point of tearing it down due to the sudden influx of HA I have seen in the sps DT. Unfortunately, the PO4 and NO3 are undetectable and this zone is the only culprit I can figure was the major change in the alst 6 months.

Would you increase flow or tear it out? I'm really uncertain if the sump rock that is only marginally lit with spill over from the DT is really that much different than a fully dedicated cryptic zone. There is some detritus build-up in the sump, but this is easily purged with a baster and only requires attention once a week. This cryptic zone is flowing less than 100gph and just seems to be a trap more than anything. I would prefer turnover from the sump, but a PH is possible but I'm concerned the detritus would just build-up inthe overflow section of the 20gal long cryptic tank before it drain back into the sump. I thought this setup would work, but the overflow from the DT (which is a BeanAnimal style coast to coast setup) is just not pushing the volume to remain detritus free.

Am I making rash decisions by removing the cryptic zone or will equilibrium ever be met with the bacteria and the influx of detritus?

 

[elegance coral]

I don't think you're being rash at all. The detritus is rotting and supplying phosphate, nitrate, and other nutrients to the hair algae. Just like compost in a garden. Remove the detritus trap, and you remove the nutrients/fertilizer it releases. There is no magic balance between bacteria and detritus that makes all the detritus simply disappear. All the bacteria do is break down detritus and release the nutrients it contains into the environment. The more bacteria you have, the faster they can release the nutrients that are locked up in detritus. The reason you aren't detecting phosphate and nitrate in the open water of the aquarium, is because it isn't staying there long enough to accumulate. You have organisms, like hair algae, that take it up to fast.

 

[DeathWish302]

I don't think you're being rash at all. The detritus is rotting and supplying phosphate, nitrate, and other nutrients to the hair algae. Just like compost in a garden. Remove the detritus trap, and you remove the nutrients/fertilizer it releases. There is no magic balance between bacteria and detritus that makes all the detritus simply disappear. All the bacteria do is break down detritus and release the nutrients it contains into the environment. The more bacteria you have, the faster they can release the nutrients that are locked up in detritus. The reason you aren't detecting phosphate and nitrate in the open water of the aquarium, is because it isn't staying there long enough to accumulate. You have organisms, like hair algae, that take it up to fast.

Unfortunately I knew the $1,000,000 nitrate factory answer you supplied, but was avoiding the inevitable. I like my reef snow just as much as the next SPS-head, but accumulation that requires daily maintenance is no added bonus of a cryptic zone IMO. As soon as I noticed the HA (that has been totally silent over the past 5 yrs by growing gthe dreaded C. Taxifolia in the lagoon) I knew somehting was up. GFO solid with PO4 at 0, check. NO3 slight pink tint to water, another big goose egg....

Then I started thinking about that ridiculous 'grunge', mud, GARBAGE that everyone was pitching as a miracle cure and of course i tried so many years ago. That stuff started the whole HA mess to begin with and hear it was again. This 'mud' that my tank has created, is acting the same as the stuff I spent money on in the past.

Anybody want to buy 14-16 1 sq. ft. eggcrate squares...... :headwallblue:

 

[mr.wilson]

Your sand bed and rock will have much more detritus than the cryptic zone. There are lots of factors that could be causing your hair algae plague. Siphoning the detritus in your cryptic zone is a start, but it won't solve the problem.

 

[Osteoclast]

Interesting read. Are there any new data to support the use of this technique? Most of the info is empirical and subjective ("my tank did this or that") or primarily hypothetical (splendid theories without proofs). Appreciate some sound science. Thanks for your input.

 

[tmz]

I think there is a lot of relevant science in the thread. Plenty of extrapolations some of which are inaccurate reaches too. Anecdotes are about all we have on atual applications .

I ran mine for several years without cleaning it out. I did a couple of months ago. There was much less detritus on the bottom of the brute can I use with water in at the bottom and out at the top than I expected; there was some ,mostly mineralized grunge.,maybe a liter or so . Removal of this material had no effect on PO4 levels or NO3 levels in the aquarium which has had virtually no nuisance algae for over 5 years coincident with the start of dosing soluble organics .
There are plenty of sponges and filter feeders on the rock in the cryptic area.

At worst it is a nice extra habitat for micro fauna and pods and extra surface area for benthic critters and bacteria .It adds to the overall water volume of the system. It's very low maintenace. I have plenty of bacteria since I dose organic carbon ,btw, so I'm not worried about the extra competition for that food source. I do not think it would substitute skimming ,organic carbon dosing, gac or othe methods but seems just fine and intersting as an add on.

 

[Osteoclast]

Thanks TMZ, I have read of your experiences before, certainly individual observations are key elements in scientific discovery and form the basis of preliminary data, often leading to controlled studies. I am asking if anything more substantial has been shown or published in this area of marine reef keeping. I realize that much of what is out there is observational and limited in scope. Thanks for your documented contributions.

 

[tmz]

I've been looking around for recent studies on the role of sponges and tunicates in terms of DIN contributions but haven't had any luck. I think that's one of the key underpinnings for the cryptic refugium idea along with food web enhancement assetions. There is one mission statement with the intent of measuring the DIN effect but that's from 2007 with no further note. Sponges are viewed as important to natural reef communities but much of what they do and how they do it is unknown even in natural reefs. So, I'm not very hopeful about aquarium based data for the time being.

Maybe someone with some relevant recent studies will chime in.