what is all of this dsb crash talk i read?

[Bomber]

Sean, those rocks must have been really full! Keep cooking.

LOL Tom.

[thackray]

"Can I keep a Marlin in my 12 gallon Eclipse?"

Only if its a mated pair!

[Randy Holmes-Farley]

A reference showing that depths to get to the anoxic regions can be deeper than in our aquaria:


Hydraulic control of pore water geochemistry within the oxic-suboxic zone of a permeable sediment. Falter, James L.; Sansone, Francis J. Department of Oceanography, University of Hawaii, Honolulu, HI, USA. Limnology and Oceanography (2000), 45(3), 550-557.

Abstract

Geochem. behavior of the top 70 cm of permeable reef flat sediment on Checker Reef, Oahu, Hawaii was examd. using spatial and temporal changes in pore water O2, NO3-, NO2-, NH4+, and N2O concns. The shallow depth of the sediment-water interface relative to the height of waves propagating across the reef creates an environment in which pore water mixing and transport are dominated by wave-induced mechanisms. Dissolved O2 penetrated 15-50 cm in the 4 study sites. Depth-integrated dissolved O2 concn. was greater under larger wave conditions and in more permeable sediment, suggesting dissolved O2 may be a good indicator of the relationship between sediment metab. and the phys. nature of the sediment environment. The absence of any subsurface N2O maxima, limited temporal variability in pore water N2O concns., and vertically coherent profiles of O2, NO3-, NO2-, and N2O suggested that sub-oxic processes are typically restricted to spatial scales that are smaller than for oxic processes in this sediment. The geochem. response of sediment to a natural perturbation was monitored by examg. the compn. of pore water immediately following a large wave event and for several weeks thereafter. Significant changes in depth-integrated O2, NO3-, NO2-, and NH4+ concns. were obsd. following the perturbation; however, only changes in NO3- lasted for several weeks after the event, whereas most other species returned to previous conditions in £2 wk.

[Bomber]

Aerobic is very inefficient.

[Habib]

It also depends on the particle size (distribution) of the sediment and the input of organics.

In other words the diffusion rate of oxygen (sediment dependent) and the uptake of oxygen (dependent an amount of organics and bacteria) determine to a large extent at what depths the sediment becomes highly oxygen depleted.

[WaterKeeper]

Originally posted by Bomber
Aerobic is very inefficient.

Another reason why I have a DSB.

Thanks for the info Randy.

[Bomber]

Uh Tom, that would be the reason to not have one.

[SPC]

A reference showing that depths to get to the anoxic regions can be deeper than in our aquaria:

This reference is for a "reef flat" environment. If we were to look at references that more closely resemble our tank environments (low flow and high organics), then we would see that the anoxic zone is not very deep.
Steve

[azra2001my]

.

[poknsnok]

hmm

[WaterKeeper]

Hi Azra
[welcome]

I see Bomber; your bare butt tank has all sorts of anaerobic areas on the glass bottom.


I know, I know Azra,

You wandered right into this discussion and it left you speechless.

[Bomber]

I know aerobic is inefficient and take advantage of that. I work it to my benefit not the other way around.

[goby1]

So how is nitrate (the ion) preferentially adsorbed at the air/water interface in a skimmer? Bomber, I didn't understand your last reply to Randy about the removal of inorganic nitrate. Randy, why not take some sort of core sample from the DSB and test it? You were wondering how to perform a meaningful test, right?

I cuss, you cuss, we all cuss for phosphorus!

G1

[Randy Holmes-Farley]

So how is nitrate (the ion) preferentially adsorbed at the air/water interface in a skimmer?

It is not. Nitrate ion is not skimmed out effectively. Organics that might otherwise break down into inorganic nitrogen (ammonia/nitrite/nitrate) are, however, sklimmed out, thereby potentially reducing nitrate.

Randy, why not take some sort of core sample from the DSB and test it? You were wondering how to perform a meaningful test, right?

Test it for what, how, and what would the results potentially show?

[goby1]

So if nitrate is not removed (once in this form), how do we suppose Bomber maintains low levels of this ion? Bomber, skimming is your only means of export, correct? Would a coil denitrator leak P? Do you suppose that increased diatom and trace algae growth, happening with slightly elevated nitrate levels, would be balanced by snail feeding, and that the snail excrement is removed by the skimmer? This is without manual removal of macroalgae.

Wouldn't the ratios of N,P, and S, as a function of depth in the sb, give an indication of the mechanism of P conversion?

Do you think that the principal reason that more people have successful reef aquariums today, as opposed to bare-bottom systems from, say, 20 years ago, is the utilization of larger pumps and more aggressive skimming?

I am enjoying this tennis match. G1

[Randy Holmes-Farley]

So if nitrate is not removed (once in this form), how do we suppose Bomber maintains low levels of this ion?

He skims out organics before they form nitrate, and what does form is used by tank organisms to grow (bacteria, algae, corals, etc).

[RichardS]

Originally posted by goby1

Do you think that the principal reason that more people have successful reef aquariums today, as opposed to bare-bottom systems from, say, 20 years ago, is the utilization of larger pumps and more aggressive skimming? G1

Good Point! I'm sure it has nothing to do with the lighting options available today.

I really enjoy this forum. The IQ levels are very impressive but I would like to ask if you could give me a little perspective of where your coming from. How about posting what levels of phosphate and nitrate you consider acceptable for whatever "system" you think works great.

On my personal tanks I consider phosphate/nitrate levels above undectable with my Salifert kits to be unacceptable.

FWIW, I have tried DSB's and am not a fan of them. I have also tried the macroalgae approach and am not a fan of that approach either.

[madmac]

Originally posted by goby1
So if nitrate is not removed (once in this form), how do we suppose Bomber maintains low levels of this ion? Bomber, skimming is your only means of export, correct?

I'm not Bomber... having lurked around long enough in these BB threads, I'd say, he skims out phytoplankton. Isn't phyto a sort of plant organism, that consumes NO3, etc jus like algae? So, I think he skims out the things that take-in NO3... a continuous harvest-and-export concept, allowing for more phyto to grow in place of those taken out and thus constantly keeping the NO3 count low.... Now, of course, I can be wrong and I'm sure you'd rather hear it from him.

[Bomber]

Originally posted by goby1
Do you think that the principal reason that more people have successful reef aquariums today, as opposed to bare-bottom systems from, say, 20 years ago, is the utilization of larger pumps and more aggressive skimming?

20 years ago most people were coming into the "natural" thing. Saving plankton, low flow, softy tanks, etc. It was even said that to be successful with "corals" = softies, you had to have a dirty tank and tanks could actually be too clean. One of the main reasons that berlin fell out of favor. Plus, running dirtier tanks was cheaper on equipment.

clueless -

The equpiment was there, but every hobby book said don't use it. That's the hobby.

If you ask bacteria to get rid of ammonium right then, where does it go? I skim out bacterial flock and phyto.

[WaterKeeper]

I'm just ribbing the Bomb. As the everybody knows, using a good wet/dry or UGF can remove 90-95% of the TOC from any tank. The anaerobic just cleans up the leftovers. A good UGF should therefore be included in a modern reef system. Efficiency counts!


And Richard; I'm not going to take comments about my limited IQ even from a LFS owner.

[boxfishpooalot]

Originally posted by WaterKeeper
Hi Azra

To Reef Central

I see Bomber; your bare butt tank has all sorts of anaerobic areas on the glass bottom.


I know, I know Azra,

You wandered right into this discussion and it left you speechless.

Lol waterkeeper, I think azra made a fake id to bump this old thread up again.....

If im wrong i apologize azra.

[WaterKeeper]

I don't know. He or she has been registered for over a year and a half and only decided to post when Steve mentioned he has a "flat" bottom.

[RichardS]

Originally posted by RichardS
I really enjoy this forum. The IQ levels are very impressive but I would like to ask if you could give me a little perspective of where your coming from. How about posting what levels of phosphate and nitrate you consider acceptable for whatever "system" you think works great.

WaterKeeper - Please tell me where I said you (or anyone) had a limited IQ. It was a compliment. I'm a literal person, if I wanted to call someone stupid I would have done so.

My question is a legitimate one. If your claiming that some filtration approach removes nitrates, phosphates, etc. then why don't you give some number that that system will yield for an average bioload. Maybe even define what you consider an average bioload.

Also what additional equipment is needed? What type of maintenance is required to maintain said system. You know, stuff like do you have to do lots of water changes, does it also require heavy skimming, and a phosban reactor, and regular use of carbon, and a light bioload and a bunch of macroalgae, and ....

It seems to me that some people do not want to have a legitimate discussion.

[Bomber]

Originally posted by RichardS
It seems to me that some people do not want to have a legitimate discussion.

Richard, Tom was kidding.

I'm not sure I'm following your question. What number for what bio-load? what average bio-load?

I'll try to tell you what I'm doing. I'm removing bacterial flock, phyto, and bacterial detritus - with a skimmer - before it sits and rots and releases things that I need more filters to take care of.

I don't know how someone would give a number on that.

Depending on what skimmer and how you run it and how good you are at getting it to the skimmer - that would decide what number of bio-load ( is that right?) you could support.

If you're not good at it, less.

[RichardS]

Originally posted by Bomber
Richard, Tom was kidding.

Oh! Perhaps I'm too literal sometimes. I really should start paying attention to those emoticons. Also maybe I'm overly sensitive since I own an LFS and you know none of us have a clue of what we are doing . My apologies.

My question is that if someone is saying that a DSB (or any other method) will effectively reduce N and P then it should be a fairly simple matter to say that in a moderately stocked aquarium with a DSB phosphates will remain below X and nitrates will remain below X.

And then to simply state what level and type of maintenance is required to maintain that aquarium (read water changes, how much & how often). Also state what additional types of filtration should be used such as skimmers, chemical filtration (types?), etc. to achieve the desired results.

I guess I was being a bit vague because I was trying not to offer my opinion of DSB's but rather I was hoping to get a clear picture of what DSB proponents consider a successful DSB system, how much work they consider acceptable, and how much additional filtration types they are using along with the DSB.

What the heck, I'll offer my opinion. After having tried using a DSB and also based on all that I have read I have come to the conclusion that the DSB is an interesting theory that simply does not work in practice. I can easily maintain very low levels of P and N simply by doing regular water changes, skimming, not overfeeding, and not over stocking. From what I have read, all of the DSB proponents are doing all of these things also (and more for some of them). So I don't understand why the DSB gets the credit for the nice condition their tank is in.