Carbon Dosing & Skimmerless

[Subsea]

Who says you can't teach an old dog new tricks? After some intense discussions on a skimmerless thread and a question posed by Randy Holmes Farley on a Carbon Dosing Maintenance Suggestion thread, I have decided to use organic carbon dosing on my skimmerless system.

The system was purchased used 12 years ago. The only change to it was in the lighting. Because of heat issues and difficulty accessing the tank for sand bed maintenance, I removed metal halides and installed BML 12K strip lights 1 year ago. One other change implemented this past Christmas was the use of a 40W UV sterilizer in dealing with my second ich outbread in 44 years of reefkeeping. I discontinued the use of UV sterilization this week in response to some of those conversations about bacteria diversity.


SYSTEM DESCRIPTION:

75G Jaubert Plenum DSB with a 30G Mud & Macro refugium modeled after
"The Ecosystem Aquarium" proposed by Leng Sy in 1997. The first section of this refugium includes a wet/dry filter using bioballs.

Nitrate Factory
Earlier this year, I conducted a 4 month test study of 7 media used in reef aquariums. Ammonia was added and monitored along with nitrite and nitrate. Each tank was feed ammonia in response to nitrate readings which were maintained between 50-150 ppm. Bioballs exceeded all media in processing nitrogen except for rock rubble. This is not a thread about bioballs. I am not interested in debating the issue. I will link the thread on Nano Reef which detailed the test study.

http://www.nano-reef.com/topic/337332-nitrate-factory/

I am a "laissez faire" reefkeeper. For me that means that I work in harmony with natural systems and I adjust where required.

Carbon dosing is a refinement to the process. I have asked some knowledgable people to recommend sources of carbon. I wish to use econominal products that are readily available in most households. Without any other research and because I enjoy Chinese food, I lean toward "sweet and sour" or vinegar and sugar.

As in all things, I seek to learn.
Patrick

 

[Subsea]

http://melevsreef.com/node/184

I meant Melvin last year at a reef conference in Austin. His detailed explanation of the process was simple to follow. Most protocoals that describe carbon dosing use reduced nitrate and phosphate to determine the required maintenance dose.

My desire to carbon dose is not driven by the need to reduce nitrate or phosphate. In my tank, hobby test kits can not measure it so I sent samples to an agriculture test lab. Their testing procedures can not measure it. I know the nutrients are in the tank, otherwise the inhabitants would cease to exist. Nitrogen and phosphrous are required for existance of life on earth.
I have to rely on my experience with observing the inhabitants of my tank and I will start with 0.4 ml of 5% vinegar each day for 60 days.

I am a laissez faire reef keeper. I keep it simple with required maintenace and stocking levels. I enjoy the simplicity of observing the tank with minimum work. For me, that means natural biological filtration.
Patrick

https://www.youtube.com/watch?v=FDt8QTAp0Cs

 

[saltyair]

From my experience and extensive reading on carbon dosing
With carbon dosing you will increase bacteria production that also use n03 and po4 to grow. You will also see an increase in sponges.
The issue of not skimming is due to the over population and die off of the bacteria in turn polluting the water quality. Im not sure if you could counter act this by having a natural organism to help balance.

Following along

 

[Subsea]

On the other hand, our studies have shown that bacterial growth appears to be carbon limited in reef aquarium water. However, there is a demonstrable difference between reef tank water in an active reef tank, and reef tank water removed from the tank. In the latter case, bacteria consumers are largely absent, and so fueling bacteria growth via carbon addition translates to rapid and large increases in bacteria population. In an active reef tank, however, this population increase is not manifest, presumably because active predation keeps the overall level in check. Thus, the highly dynamic nature of bacteria populations in the water column of reef aquaria is highlighted by these studies. From a different perspective, the bacteria population in a reef tank seems to act as a buffer to help dissipate the otherwise potentially serious negative consequences of (inadvertent?) tank pollution via rapid carbon addition, at least perhaps up to a saturation point.

The above paragraph is in the conclusion section from an article in Advanced Aquaria March of 2011. Bacteria populations in established reef tanks are kept in check due to active predation. Active predation refers to food gathering by many micro fauna, including sponges, NPS, filter feeders which includes coral.
Patrick

Feature Article: Bacterial Counts in Reef Aquarium Water: Baseline Values and Modulation by Carbon Dosing, Protein Skimming, and Granular Activated Carbon Filtration
By Ken S. Feldman, Allison A. Place, Sanjay Joshi, Gary White
What are the bacteria populations in the water column of reef tanks, and how does that value compare with bacterial counts in authentic reef water? Does carbon dosing indeed increase water column bacteria populations (i.e., is growth carbon limited)? Does mechanical filtration (protein skimming and/or GAC filtration) actually remove bacteria from the water column, and if so, how much? Ken, Allison, Sanjay, and Gary's in-depth article puts these questions to the test.

comments 19 Comments
CONTENTS
1. Introduction
1.1 The goal of our study - testing the validity of the Carbon Dosing hypothesis
1.2 Bacteria: A general introduction
Bacterial Physiology
Bacterial Surface Charge and Protein Skimming
1.3 Bacterial life processes
Bacterial Metabolism
Bacterial Growth
Bacterial Nutrients
Manipulating Bacterial Growth
The Coral Holobiont
"Probiotic" Application of Bacteria
1.4 Counting bacteria in the water column
2. Experimental Approach
2.1 General experimental
2.2 Control experiments and bacterial contamination
2.3 Data workup
3. Results and Discussion
3.1 Baseline bacteria counts
3.2 Carbon dosing (planned and inadvertent) - How does it affect water column bacteria levels?
3.3 Bacteria removal via mechanical filtration - how effective?
4. Conclusions
5. Acknowledgments
6. References
Departments of Chemistry (Ken S. Feldman, Allison A. Place) and Industrial and Manufacturing Engineering (Sanjay Joshi), The Pennsylvania State University, University Park, Pennsylvania 16802, and Route 66 Marine, Gardena, California (Gary White)


The following paragraph at the beginning of the article should be an eye opener for reef hobbiest.
Patrick

Our earlier research on the topic of carbon nutrient levels in marine aquaria (Feldman, 2008; Feldman, 2009; Feldman, 2010) has provided experimental documentation for four conclusions that impact on TOC management in our reef tanks:

Reef aquaria utilizing active filtration (GAC, skimming) maintain equilibrium TOC levels within the range found on healthy tropical reefs.
Protein skimming (i.e., bubbles) is not very effective at removing TOC from aquarium water, depleting typical reef tank water of only ~ 20 - 35% of the post-feeding TOC present.
GAC filtration is quite effective at stripping reef tank water of its TOC load, removing 60 - 85% of the TOC present.
And, quite intriguingly, the natural biological filtration, which starts with bacteria and other microbes, is remarkable in its capacity to remediate reef tank water of TOC, easily removing 50% or more of the post-feeding TOC increase in tank water.
Conclusions (2) and (3) describe the consequences of mechanical filtration on TOC levels, but the 4th conclusion emphasizes the importance of the "hidden" part of the remediation equation, bacterial predation, for gaining an understanding of the dynamics of carbon commerce in our aquaria. In fact, this observation, coupled with the advent of Carbon Dosing strategies for nutrient export, led to a new series of questions regarding the perhaps pivotal role of bacteria, or at least skimmable water column bacteria, in successful reef aquarium husbandry.

 

[Subsea]

For my natural systems I focus on the fourth conclusion of this earlier study. It emphasises the hidden part of the dynamic processes, bacteria predation. The predation of bacteria happens on many levels. I focus on filter feeders and corals which are active consumers of bacteria. Lowering nitrate and phosphate is not an issue in my extablished system. My inexpensive test kit can not find any levels of these two nutrients but I know that they are there by the growth of macro algae. I have sent samples off to be tested at agriculture test labarotories with levels that were undecttable at the level of their test procedures. Even without this documentation, I know that nitrates and phosphate are in the tank. Otherwise corals, macro algae and bacteria populations would all decline.
I am all for contributing to the healthy growth of bacteria populations. Without healthy bacteria populations, the Martians in War of the Worlds would not have been defeated and earth as we know it would cease to exist. While the reference to the Martians is an attempt at satire, the second part to the sentence is that healthy bacteria populations are mandatory for biological life to exist on earth. Considering that nitrate and phosphate reduction is not required, I do not need to export the bacteria which reduces nitrate and phosphate. For my purposes, protein skimming is counter productive. The Feldman experiments support Paul's statement that bacteria in the water column will reproduce as fast as the skimmer removes them. Feldman's last statement at the end of the scientific paper questions the long term health of corals in our captive ecosystems due to skewed populations effecting diversity. He ends with the conclusion that more test are required.

In researching articles of carbon dosing, initial comments say that protein skimming is required and not to carbon dose with DSB in place. Melvin's Reef has an article on his successes with carbon dosing with DSB methods. Considering that the barameter that establishes the right dose are reducing nitrate and phosphate readings, I proceed with,caution. In my quest to provide food for bacteria diversity, I will start with 0.4 ml of 5% vinegar and observe results for the next 60 days.
I seek to learn.
Patrick

Scot,
In reading the article about details on testing controls, it was pointed out that with the use of Red Sea salt, a significant increase in bacteria populations were noted. This was due to the nature of some salt coming from evaporative beds producing dried crystals. Considering that bacteria can exist in this dehydrated salt crystals, your concern about bacteria diversity introduction has another method to correct the concern.


__________________

 

[Subsea]

From my experience and extensive reading on carbon dosing
With carbon dosing you will increase bacteria production that also use n03 and po4 to grow. You will also see an increase in sponges.
The issue of not skimming is due to the over population and die off of the bacteria in turn polluting the water quality. Im not sure if you could counter act this by having a natural organism to help balance.

Following along

GAC is twice as effective at removing TOC than protein skimming. It also removes noxious chemicals that foam fractionization can not remove. Partial water changes dillute these chemicals but GAC will remove them completely. For that reason I use small amounts and change frequently. Considering that the biological filtration uses these bacteria to produce a proliferation of micro fauna and fana. Why remove bacteria if they are food for the tank? It is a Question of Balance by the Moody Blues.
Patrick Castille

 

[hypnoj]

following

 

[Subsea]

One recipe for vinegar dosing recommended 0.1 ml of 5% acetic acid for every 25G. With 75G DT and 30G refugium I calculate 0.4 ml. That amount seems insignificant to me. How can such a small amount of 5% vinegar effect pH?
Patrick

That is an extremely low dose. I've dosed more than 1 mL per gallon of total system volume for an extended period, but concluded it was too high. I currently dose about 0.3 mL per gallon total system volume.

As to the pH effect, 1 mL of distilled white vinegar per gallon of aquarium water will achieve an initial pH drop of about 0.3 pH units (depends, of course, on the tank alkalinity and also the starting pH).


__________________
Randy Holmes-Farley



Originally Posted by Subsea View Post
Tom,
One recipe for vinegar dosing recommended 0.1 ml of 5% acetic acid for every 25G. With 75G DT and 30G refugium I calculate 0.4 ml. That amount seems insignificant to me. How can such a small amount of 5% vinegar effect pH?
Patrick

Not much pH effect short or long term at that level. Not much extra organic C either. I think that may be a very/overly safe start up recommendation coupled with an amp up plan. You can probably go higher and faste; though, a smallish dose may be what you want since NO3 and PO4 are low.

I can dose 80ml of vinegar to 650 gallons with only a small downward twitch( < 0.1) in pH when it's dosed. It recovers in an hour or so. More than that needs to be spread out to avoid a significant downward pH spike,IME With a dose of vodka and vinegar equivalent to about .6ml vniegar per gallon ( 36 ml 80 proof vodka an 80 ml vineagar).

For clarification ,any organic carbon source will increase bacterial activity which produces CO2 which lowers the pH. Acetic acid does it quickly at the star but in the end any source gets about the same pH variation. With my dose( a dose of vodka and vinegar equivalent to about .6ml vniegar per gallon ( 36 ml 80 proof vodka an 80 ml vineagar).
in my sytem , pH dropped 0.15. I got it back to 8.15 /8.35 dialy wing with a CO2 scrubber.
tmj

For organics reduction from the system, I will export macro algae as compost for my tomatoes. For TOC reduction, I will use GAC. For gas exchange, I will use wet/dry filter with bioballs.
Patrick

Vinegar is fine at low volume or dosed slowly at high volume.

Plain vodka has no sugar; it's just ethanol and distilled water. The carbohydrates and sugars have already been fermented to the ethanol.
tmj



Time of dosing was recommended early in photo cycle. What implication does this have? With photosynthesis, oxygen will be given off and carbon dioxide consumed. Is the bacteria response to carbon source so quick that their use of oxygen and expelling CO2, synchronized with the opposite cycle of photosynthesis?
Patrick

Vinegar dumps a lot of H / CO2 when initially dosed quickly. These bacteria do seem grow quickly. Dosing during photosynthetic periods helps mitigate the pH effect and the potential oxygen depletion.
tmj




__________________
Tom

Current Tank Info: Tank of the Month , November 2011 : 600gal integrated system: 3 display tanks (120 g, 90g, 89g),several frag/grow out tanks, macroalgae refugia, cryptic zones. 40+ fish, seahorses, sps,lps,leathers, zoanthidae and non photosynthetic corals.
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Distinguished gentlemen,

Thank you for your guidance. I will begin dosing 25ml of 5% vinegar for 30 days. If no changes, I will increase dosage to 40ml per day, which will be dosed at the beginning of the photo cycle.
Cheers,
Patrick

 

[Randy Holmes-Farley]

:thumbsup:

Good luck!

 

[ganjero]

My desire to carbon dose is not driven by the need to reduce nitrate or phosphate.

Sorry if I missed it, but what are you trying to achieve with carbon dosing?

 

[VonUberReefer]

Tagging along!

 

[Subsea]

Sorry if I missed it, but what are you trying to achieve with carbon dosing?

Carbon grows bacteria populations. Bacteria are food for coral and filter feeders. Bacteria predators abound in reef tanks, sponges, tube worms, flame scallops, sea apples and lastly corals.
My present micro fauna and fana population is diverse. Coupled with mud and macro filters, nitrates and phosphates are undetectable. Carbon dosing is a very clean way to provide for the bottom of the food chain.
Patrick

 

[ganjero]

Interesting, I am subscribing.

 

[Subsea]

Why skimmerless? Mainly, because I do not think that it is necessary. In googling TOC consumers in reef tank, I found this link:

http://www.advancedaquarist.com/2008/8/aafeature3/

Which organisms produce carbon, and which organisms consume carbon in a reef environment?
The major consumers of the DOC in the reef environment are heterotropic (= can't make their own food) bacteria (Moriarty, 1985). These bacteria can be living in the water column or tightly associated with substrate, detritus, corals and other benthic organisms, etc. Bacteria are a critical component in the food web of the reef, as they occupy the role of "middle man" in the transfer of energy from the source (= sunlight) to the consumers on the reef (Eppley, 1980; Ducklow, 1983, Crossland, 1980; Johannes, 1967; Ducklow, 1979; Gottfried, 1983). Sunlight impinging on the reef kicks off the energy cycle by promoting photosynthesis within free-swimming plankton in the water column and also within the zooxanthellae of the scleractinian corals that we obsess about in our aquaria. Photosynthesis utilizes the sunlight's energy to "fix" (= attach) inorganic carbon in the form of CO2 to organic chemical structures that eventually become carbohydrates (cf. Fig. 1). These carbohydrate building blocks are chemically manipulated further by the zooxanthellae and/or the coral host and then secreted by the coral as coral mucus (a combination of complex polysaccharides, amino acid oligomers/polymers, lipids, etc., cf. Fig. 1). The carbohydrates and amino acids within the mucus serve as food sources for the bacteria and other microbiota that comprise the foundation of the marine food pyramid (Kirchman, 1990; Rich, 1996; Weiss, 1999; Wild, 2004; Sharon, 2008). The remaining reef inhabitants, including the very corals that house the zooxanthellae, then feed on these energy rich microbes (or, in turn, on the organisms that eat the microbes, ad infinitum), thus perpetuating the reef's nutrient recycling food web. In addition to corals, sponges are some of the most prolific repositories of marine bacteria. In fact, some sponges have been studied as effective bioremediation agents in marine aquaculture as a consequence of their exceptional ability to absorb TOC (Fu, 2007).

Where does the DOC come from? Phytoplankton are major contributors, and the intriguing hypothesis that DOC release is a means to dispose of excess, photosynthetically generated "fixed" carbon when nutrient levels are not high enough for growth, has been proposed (Hessen, 2008). As discussed above, some of the major producers of DOC on the reef are the corals themselves (Crossland, 1987). Using some rather creative carbon-balance accounting, Sorokin has estimated that ~ 20% of the DOC in the waters of a tropical reef can be attributed to coral mucus production (Sorokin, 1993). In an independent study, a similar value (10 - 20%) of the total TOC that is metabolized by the reef's sedimentary community was attributed to coral mucus (Wild, 2004); Johannes, using different estimation methodology and at a different locale, scales this value back to ~ 2% (Johannes, 1967). Even given the large error bars in these numbers due to the assumptions made, it is astonishing that the corals contribute so much organic material to the reef water column, and by inference, to the closed systems of our (overstocked?) reef aquariums.

Several additional lines of evidence support the contention that corals, via their mucus secretions, literally flood the reef with DOC. For example, measurement of the DOC content of the contact surface water surrounding Montastraea faveolata and Madracis mirabilis on a reef near Curacao NA resulted in higher values (~ 2.28 ppm) compared with nearby reef water (1.60 - 1.94 ppm) (van Duyl, 2001). In another (laboratory-based) study, Galaxea fascicularis was observed to emit a DOC "spike" every morning and every afternoon lasting about an hour. Specimens fed with artemia secreted a larger DOC spike compared to unfed control: for the fed Galaxea, the measured DOC value within a 5 liter reservoir raised from a base value of 1.2 ppm up to 4.8 - 20.4 ppm; unfed Galaxea raised the base DOC level of the water only a few ppm during the spike emission. In both cases, within 2 hours of the spike, the DOC content of the reservoir fell back to basal levels (Ferrier-Pagès, 1998). Carbon balance calculations suggested that ~ 11-14% of the photosynthetically fixed carbon (i.e., originating in HCO3- <-> CO2) is released as DOC, a value in line with many prior studies (Sorokin, 1993; Crossland, 1987).

More coming,
Patrick

 

[Subsea]

Whats in the skimmate?

Introduction; in part.

You are here: Home › Volume IX › January 2010 › Feature Article: Further Studies on Protein Skimmer Performance
Feature Article: Further Studies on Protein Skimmer Performance
By Ken S. Feldman, Kelly M. Maers
Department of Chemistry, The Pennsylvania State University, University Park, PA 16802. Many factors contribute to the 'value' of a skimmer to an aquarist, including quality of construction, size, footprint, noise level, ease of cleaning, energy efficiency of the pump, and of course, the ability to remove organic waste from aquarium water.


CONTENTS
The Modified Mathematical Model
The Math Behind It
The Experimental Design
Results
Skimmer Comparison Studies
Conclusions
Acknowledgments
References
We published a paper on skimmer performance in the January 2009 issue of Advanced Aquarist magazine that detailed, for the first time, an experimental methodology to provide meaningful metrics for both the rate at which skimmers removed organics and the extent of the removal of these organics from aquarium water (Feldman, 2009). Highlights of these earlier studies included:

Development of a mathematical representation of the skimming process based upon a "continuously stirred reactor" model for both the skimmer and the reservoir (tank) with a given water flow rate between them.
Application of that mathematical formalism to both (a) a model system featuring removal of Bovine Serum Albumin (BSA) as a test case protein in freshly prepared saltwater, and (b) authentic TOC (Total Organic Carbon) removal in reef tank water. Key experimental parameters extracted from this mathematical modeling included the rate constant, k, for organic (BSA or TOC) removal, which is a singular metric reflecting the intrinsic capacity of a given skimmer to remove the organics in question, and the total % of the available organics (BSA or TOC) that were removed before the skimmer "flatlined".
Analysis of these data for four representative skimmers; a EuroReef CS80 needlewheel skimmer, a Precision Marine ES100 venturi skimmer, a Precision Marine AP624 airstone skimmer, and an ETSS Evolution 500 downdraft skimmer.
Conclusions about relative skimmer performance based upon these measurements:
All four skimmers removed both BSA and TOC with similar rate constants; in short, "bubbles is bubbles", and there was no significant difference between these four skimmers in their intrinsic abilities to strip organics from saltwater.
Only about 20 - 30% of the measurable TOC in reef tank water was removed by skimming, whereas almost all of the BSA was removed from saltwater by skimming.

In the last paragraph before the conclusion, Feldmen discribes the selective removal of certain bacteria types at the molecular level due to thermodynamics and hydropobic surfaces.
The discussion is above my pay grade, but I understand the implications.
Patrick

One of the more surprising and important observations to emerge from the earlier skimmer studies was that the four original skimmers tested removed only 20 - 30% of the measurable TOC in the reef tank water examined; the remaining 70 - 80% of the TOC was not removed by skimming. Extension of these measurements to the three new skimmers tested in this study did not add much to the argument. The Reef Octopus' removal amount fell within this range, whereas the Bubble King and Royal Exclusiv skimmers appeared to remove incrementally more of the extant TOC, perhaps up to the mid-30% range. An explanation for this observation was offered in the January 2009 Advanced Aquarist article; in summary, skimmers can only remove what bubbles trap, and bubbles only trap molecules and/or particles (i.e., bacteria, diatoms, etc.) with some compelling thermodynamic reason to adhere to the bubble's surface. On the molecular level, this surface association is typically driven by the molecule/particle having a hydrophobic (= water hating) patch that can be buried in the bubble surface/interior. This arrangement avoids the energetically penalizing juxtaposition of hydrophobic surfaces with (hydrophilic) water, and so overall the system energy is lowered (a favorable occurrence). Some of the molecules/particles in aquarium water will meet this hydrophobic region criterion, and some will not. The ones that do not have a sufficiently large hydrophobic patch will not interact with bubbles, and hence will not be removed by skimming. From, the results of the experiments described here, it appears that only 20 - 35 % of the measurable TOC meets this hydrophobicity criterion (= [TOCl] defined earlier) whereas the remaining 65 - 80 % does not (= [TOCr] defined earlier). In essence, bubbles are a rather poor media for removal of organic nutrients from aquarium water compared to, for example, GAC. However, they do have the distinct benefit of being cheap.

 

[Subsea]

What is in the skimmate: details

http://www.advancedaquarist.com/2010/2/aafeature

Introduction:

he rather counterintuitive observation that protein skimmers remove only 20 - 35% of the measurable Total Organic Carbon (TOC) in reef aquarium water (Feldman, 2009; Feldman, 2010) begs the question, "what is all that "stuff" that collects in our skimmer cups?" Is it really TOC, or at least a labile, or "skimmable", fraction of TOC? Attempts to identify TOC components from authentic ocean water are still in their infancy, and to date this material has resisted detailed chemical analysis. Recent efforts primarily by Hatcher and colleagues (Mopper, 2007; De la Rosa, 2008) using sophisticated mass spectrometry and nuclear magnetic resonance spectroscopy techniques have revealed that authentic ocean TOC is comprised of tens of thousands of discrete compounds that include chemical representatives from all of the major biochemical groups; lipids, peptides, carbohydrates, heterocycles, aromatics, etc. The relationship between ocean TOC and aquarium TOC still remains to be established, but it seems likely that the TOC in our aquaria is equally diverse and rich in its chemical complexity. Thus, it is equally unlikely that a chemical breakdown of aquarium TOC will be forthcoming in the near future. Nevertheless, there are analytical methods that can reveal and quantify most of the elemental components of TOC, and with a little chemical intuition, allow for the assignment of some of these components to chemical categories. These analytical methods are called Elemental (or Combustion) Analysis and Inductively Coupled Plasma Atomic Emission Spectroscopy. Both methods are available from many commercial operations; we used Columbia Analytical Services in Tucson AZ for our skimmate samples (http://www.caslab.com/).

Conclusion:

The chemical/elemental composition of skimmate generated by an H&S 200-1260 skimmer on a 175-gallon reef tank over the course of several days or a week had some surprises. Only a minor amount of the skimmate (solid + liquid) could be attributed to organic carbon (TOC); about 29%, and most of that material was not water soluble, i.e., was not dissolved organic carbon. The majority of the recovered skimmate solid, apart from the commons ions of seawater, was CaCO3, MgCO3, and SiO2 - inorganic compounds! The origin of these species is not known with certainity, but a good case can be made that the SiO2 stems from the shells of diatoms. The CaCO3 might be derived from other planktonic microbes bearing calcium carbonate shells, or might come from calcium reactor effluent. To the extent that the solid skimmate consists of microflora, then some proportion of the insoluble organic material removed by skimming would then simply be the organic components (the "guts") of these microflora. These microflora do concentrate P, N, and C nutrients from the water column, and so their removal via skimming does constitute a means of nutrient export.

 

[2_zoa]

Your doing this in your 75 gallon tank right? It has a deep sand bed right?

I thought large populations of bacteria used up oxygen levels to the point of losing fish? I remember reading about a tank (160ish gallons) in coral a few years ago who had a DSB and they weren't dosing any carbon sources and they had to keep a skimmer going due the bacteria population. They had to keep the tank aerated.

How do you intend to quantify your test? What will you consider to be a success? How will you know you made it to said point?

 

[Subsea]

For my needs, I observe the results and decide if I like it. It is very little commitment on my part. After 44 years of reefkeeping, I have settled on laissez faire. I enjoy my reef tanks without having to prove anything. The idea of balancing nutrients in with natural biological filters is easy enough to accomplish. The idea of using vinegar as a carbon building block is a lot cleaner than a bunch of food added to the tank.

To your point about DSB using oxygen. After 44 years of experience with DSB, I am aware of that need. Using a surface skimmer and gravity feeding water to wet/dry filter with a reverse photo cycle has worked fine for me. Did you look at the link to Melvin's Reef on post #2. It documents 5 years of carbon dosing/skimmerless with a DSB. As in all things, it is a Question of Balance.
Patrick

 

[Randy Holmes-Farley]

IMO, this is a good experiment to see what happens when carbon dosing and skimmerless.

While I think my carbon dosing (vinegar) increases food for creatures like sponges, not skimming might increase it still further (I skim).

It may also help clarify how important skimming is in exporting nutrients in an organic dosed system long term. As far as I know there is no real info on that method.

 

[2_zoa]

For my needs, I observe the results and decide if I like it. It is very little commitment on my part. After 44 years of reefkeeping, I have settled on laissez faire. I enjoy my reef tanks without having to prove anything. The idea of balancing nutrients in with natural biological filters is easy enough to accomplish. The idea of using vinegar as a carbon building block is a lot cleaner than a bunch of food added to the tank.

To your point about DSB using oxygen. After 44 years of experience with DSB, I am aware of that need. Using a surface skimmer and gravity feeding water to wet/dry filter with a reverse photo cycle has worked fine for me. Did you look at the link to Melvin's Reef on post #2. It documents 5 years of carbon dosing/skimmerless with a DSB. As in all things, it is a Question of Balance.
Patrick

I did not look at that link. Thank you for clarifying. As, to doing to see if you like the result. That's awesome. You are the only one that really matters and your absolutely right. All things in moderation.

Stay dry man. Prost.:beer: