last month I reviewed how the reefkeeping hobby is filled
with seemingly "new" ideas that are periodical and
cyclical in nature. Some historical and current trends by
which reef aquarists seem to constantly "re-invent"
themselves were discussed, and in this article I will detail
my thoughts on another such trend, namely, adding vodka to
Since some European countries have been instrumental in advances
in reef aquarium techniques, there is often a perceived impression
that their knowledge and skills are something to be awed.
Having seen, visited, and been involved with aquarists in
any number of European countries, I can say that the average
state of the hobby overseas is similar to what it is in the
United States. There are some great aquarists, there are some
moderately successful aquarists, there are some struggling
aquarists, and there are a slew of people who probably should
never have bought the tank in the first place. Europeans also
regularly complain about a lack of informative material available
in their native language, and periodicals from Britain, Italy,
France, Germany, and other countries are similar to those
offered here. In other words, there are some articles of value,
and some that probably should have been left in the editor's
trashcan rather than appearing in print. My initial point
in this subject is that just because Europeans have better
cheese, bread, and architecture than we do does not necessarily
make them omnipotent, or even desirable, as reef aquarium
authorities. I might also add that one of the best vodkas,
surprisingly, is made right here in my home state of Texas;
a gold-medal winning brand named Tito's handmade vodka which,
when mixed with fresh-squeezed ruby red grapefruit juice,
ice, and a squeeze of ripe Mexican lime, may not be ideal
for the reef aquarium, but which does offer some benefit to
the aquarist on hot summer nights.
The "Theory" Behind Ethanol Additions
A German magazine
recently published an article suggesting and recommending
the dosing of ethanol (as vodka) to reef tanks as a carbon
source for marine heterotrophic bacteria in order to increase
denitrification rates and bacterial biomass production (Mrutzek
and Kokott 2004). Further, they claimed that additions cause
rapid declines in nitrogen and phosphorus produced by fish,
invertebrates, and algal metabolism (ironic, since many aquarium
invertebrates and algae are sinks, not sources, for nitrogen
and phosphorus). In turn, the bacteria provide a food source
for corals and other filter feeders. The method is recommended
particularly for those tanks that are highly skimmed (and
probably lack particulate material) and which lack sand beds.
Tanks with sand beds or other sediment-based systems, they
mention, react unusually and may have adverse effects to ethanol
"Experiments" were performed (and I use the term
experiment loosely to mean the typical uncontrolled, unreplicated,
statistically insignificant sort of "let's add it, see
what happens, and produce results that show how my tank never
looked better" sort of trials that are often found in
aquarium literature). The results showed a precipitous decline
in nitrogen and phosphorus levels over approximately one month
with increasing doses of vodka. The sample size for the experimental
procedure was one (n=1), consisting of a single person's personal
home aquarium. There were no controls in the experiment (i.e.
an identical tank without vodka being added to see if there
actually were results from the treatment). In fact, the sample
tank received an increasing dose of vodka during the treatment,
making any dosing effect impossible to determine. Additional
support for the "experiment" was collected by casual
replication in completely different trials in even less controlled
conditions; that is, other aquarists began adding vodka and
claimed similar "results."
Results of this work also showed a number of other effects.
A large "bloom" occurred which clouded the test
tank, an occurrence that could and often does kill tank inhabitants.
It was assumed the bloom was bacterial, but no mention was
made if and how the cloudiness in the tanks was determined
to be bacterial. Given what I will offer below, it may also
have simply been carbonate precipitation brought about by
additional carbon addition and possibly microbial mediation.
Having fortuitously escaped tank mortalities, the tank cleared
and the authors literally state how "the tank water had
never been clearer, the coral polyp extension was better,
and the coral coloration was more intense." Where have
I heard this before? The observed decrease in nitrate and
phosphate is an interesting effect, but I will discuss this
in more detail below.
Critique of the Method and Discussion
Without yet addressing
the biological premise behind this concept, I feel the need
to address other parts of the article. There are a number
of statements and assumptions made by the authors which are
unsubstantiated, not factual, or questionable.
The authors state that increased levels of nitrate cause
decreased coral growth rates in their rationalization for
ethanol-based reductions, but there are conflicting studies
on this subject. There have been many studies that have shown
declines in coral growth with increased levels of nitrogen
(as ammonia or nitrate), as well as those which have shown
increased coral growth with increased levels of nitrogen (as
ammonia or nitrate), or no significant effects at all. The
extensive works that exist on the subject discuss the effects
of increased nitrogen on tissue growth, linear extension,
calcification rates, reproduction, settlement rates, and other
aspects of coral biology. Generally, increases in ambient
levels of phosphate have been implicated in reduced coral
growth, although recent works also conflict in this regard.
ENCORE studies (Steven and Broadbent 1997), for example, showed
a 29% increase in skeletal biomass with phosphorus enrichment
in Acropora palifera. As stated in the article, "several
recent field studies have found no change in growth rates
in response to putative elevated nutrient concentrations,
and challenge the dogma that corals can only grow in oligotrophic
conditions as an oversimplification of processes that govern
the growth of these organisms." Most recently, the discovery
of corals harboring symbiotic extracellular bacteria (Rohwer,
et al. 2001, 2002) and intracellular cyanobacteria
(Lesser, et al. 2004) to provide a source of reduced
nitrogen emphasizes the normally nitrogen-limited growth of
corals in very low nitrogen environments such as coral reefs.
The authors write that denitrification occurs only in anoxic
environments, and further state that such areas only occur
deep within live rock or within sand beds. Their opinion is
that tanks lacking sand beds may not have enough denitrification
capability within the pore structure of live rock to process
the metabolic or aquarist-provided nitrogen inputs to reef
tanks. First, no denitrification rates, to my knowledge, have
been measured in aquarium sediments or substrates outside
those provided by Toonen (although they have been measured
often in the field, as discussed below). Thus, the statement
is speculative, at best. Second, most aquarists using live
sand beds believe that top aerobic (oxic) layers overlay the
anoxic layers where denitrification takes place. However,
denitrification can also take place in oxic areas, and some
of the highest rates of denitrification have been found in
the top 1 cm of sediments where nitrate and oxygen levels
are highest (Oren and Blackburn 1979). Denitrifying zones
can occur from the top millimeter down to 10-15 cm or more,
such as in the sediment areas near the Bermuda shelf. Nonetheless,
anoxia commonly develops in the top 1/2" to 1" (5mm
- 10 mm) of reef sediments, though this depth varies according
to the grain size, bioturbation levels, water flow, physical
sediment shifting, dynamic pockets of transient organic enrichment,
and composition of the substrate. Areas without bioturbation
may become anoxic within millimeters of the (carbonate) mud
surface of shallow water sediments (Matson, 1985).
Moreover, denitrification has been shown to be a nitrogen-limited
and not a carbon-limited process, though carbon limitation
is central to the premise of the vodka-addition treatment.
Without question, the denitrification process is microbially
mediated, but unfortunately little, if any, evidence exists
that microbial populations in aquariums are carbon-limited.
In fact, in the presence of adequate light and a tank full
of corals, along with buffer additions, kalkwasser additions,
and normal gas exchange, carbon should be available in excess.
There are studies that support the carbon-limitation of heterotrophic
bacteria in marine bacterioplankton (Kirchman, et al.
2000), but these same studies along with others, also indicate
iron, phosphate, or nitrate limitation in the same waters
under different conditions. What conditions exist in a particular
aquarium, what bacteria can be expected to "bloom,"
and how the system responds is far from assured. Also, denitrification
probably does not appreciably occur in most anoxic environments,
but is closely coupled with nitrification and occurs predominantly
at the oxic/anoxic interface. In anoxic sediments, sulfate
reduction seems to be the primary pathway, although even sulfate
reducing bacteria are found in oxic environments (Dilling
and Cypionka 1990; Ramsing, et al. 1993; Teske, et
al. 1998; Minz, et al. 1999b; Minz, et al.
1999a; Fournier, et al. 2002; Schramm, et al.
1999; Sigalevich, et al. 2000). Sulfate reducers occur
primarily in enriched lagoon sediments, and they are also
associated with cyanobacterial mats in the reef flats (Kinsey
1985). The end product of their decomposition is carbon dioxide,
which can contribute greatly to the CO2
content of the water.
Because of hydrodynamics across surfaces, microbial community
dynamics, and other biotic and abiotic influences, oxic/anoxic
zones can be found virtually everywhere in an aquarium. Denitrification
has been found to exist on the surface of detrital particles,
on the surface of corals, and on the surface of sand grains
that are found in oxic environments. Therefore, denitrification
and even sulfate reduction can be considered microaerophilic
processes that do not depend on anoxia to take place. A microbiota
adapted to the anoxic zone below the RPD (Redox Potential
Discontinuity) environment can decompose organic material
through fermentation, where some organics are used as hydrogen
acceptors for the oxidation of other compounds, yielding end
products such as fatty acids and dissolved sulfates. Nitrates,
carbonates, and water can be used as hydrogen acceptors by
different bacteria, yielding compounds such as H2S,
NH3, CH4, etc.
These are not ordinarily thought or propounded to be compounds
desirable in captive conditions, yet the typical flora and
fauna in a live rock-based system thrives on these exact compounds.
Furthermore, plants are able to utilize denitrification pathways,
and aquariums contain high numbers of these; macroalgae and
photosynthetic single-celled organisms, endolithic fungi,
bacteria, coralline algae, and highly grazed turf species
are among those functional biotic components present but remaining
largely unseen or not considered in such speculations on nitrogen
dynamics in tanks, and none of which are requisite to the
presence of a sand bed. Sponges have been found to be able
to denitrify, too, through their association with endosymbiotic
bacteria. Corals are covered with a rich microbial surface
community that includes many alpha- and gamma-proteobacteria
that are known to be denitrifiers. In fact, anoxia is now
known to exist within coral tissues at night, and studies
are underway to determine how corals are able to survive this
environment (Kulhanek, et al. 2004). Ultimately, the
individual rates of denitrification within aquaria are probably
largely dependent on an incalculable number of factors. If,
and why, denitrification or phosphate accumulation is occurring
in individual tanks is probably equally varied, and judging
by the number of relatively novice reefkeepers in this country
reporting immeasurable nitrate and phosphate levels, the problem
may not be so widespread or insurmountable as is inferred
by the authors.
Upon finishing the results section of this article, and progressing
to the discussion, barely a sentence existed which could be
taken as correct. I would urge those so inclined to read this
article to completely skip the discussion section. Virtually
every statement concerning disease nutrient processes, and
microbial ecology is conjecture and, in many cases, simply
wrong. This is unfortunate, because if the authors had a better
grasp of the processes occurring, had done adequate work to
confirm their speculations, and focused diligently on a good
experimental protocol, the effects noted in terms of such
mismanaged aquaria that have high nitrogen and phosphorus
levels (that admittedly are common enough) and their response
to carbon inputs might lead to valuable developments (though
I doubt a dosing schedule for vodka across all reef aquariums
with such issues would be possible).
"Of course, if one ignores contradictory observations,
one can claim to have an 'elegant' or 'robust' theory. But
it isn't science." - Halton Arp, 1991, from Science
News, Jul 27.
Lesson Learned: The Later Years
There are two major keys to success with reef aquaria:.
Quarantine and Patience. The end. (But, reading, light,
food, and water flow don't hurt either).
Some Studies on the Subject
"There is something fascinating about science. One
gets such wholesale returns of conjecture out of such a trifling
investment of fact." - Mark Twain (1835 - 1910).
The amounts of bacterial
populations present in sediments depend to a large degree
on particle size (Rublee 1982, Ransom, et al. 1999).
They are the highest in very fine sand year round and in very
coarse sand during the winter (Johnstone 1990, Matson 1985).
Sediments are generally oxidized in winter, and reduced in
summer since higher temperatures favor higher anaerobic activity.
Coarse sand has higher photosynthesis rates of algae within
the sediments, and in overall respiration of the community
(Johnstone 1990). Even coarse-grained sediments have a rate
of anoxic catabolism that equals oxygen reduction (Matson
1985). Bacterial populations in sediments, as mentioned above,
may even be nutrient limited (Hansen 1987) by phosphorous
or nitrate; in other words, they are so effective that they
could theoretically process more organic material than the
amounts to which they are exposed. Anoxic decomposition, via
reduction, is the most completely regenerative method of disposing
of excess nutrients, and could account for the decomposition
of all deposited organic matter to the lagoon (Matson 1985).
The same findings have been applied to seagrass meadows and
mangroves, and I have never seen any sand bed in an aquarium
anywhere nearly as foul and organically enriched as some of
these habitats that reek of hydrogen sulfide (and yet still
harbor a tremendous variety of filter feeding invertebrates,
sponges, and even corals).
The sediments that surround and lie adjacent to coral reefs
can be quite high in organic matter, especially in small pockets,
and play an integral role in denitrification and nutrient
processing. The highest rates of denitrification on and around
the reef are found in dead coral heads (this is the equivalent
of live rock to aquarists), Thalassia seagrass beds
and lagoon sediments (Seitzinger and D'Elia 1984). The fact
that dead coral heads show such high rates of denitrification
seems to contradict the notion that live rock is an ineffective
substrate as posed in the above-mentioned article. It is conceivable,
however, and perhaps likely that the biomass per volume of
water in tanks exceeds the abilities of live rock to process
organic and inorganic nutrients, but this additional amount
is met easily by utilization of a sand bed by aquarists as
evidenced by extremely low nutrient levels found in the water
column over long periods of time. I am quite sure no work
has been done to obtain meaningful measurements of organic
enrichment as an average value in reef aquariums, but observation
would suggest that they are significantly enriched by comparison
with an equivalent sand depth around coral reefs, and perhaps
about equivalent to offshore Thalassia meadows (but
less enriched than nearshore communities). If this estimate
is even remotely reasonable then, if anything, the sand beds
of tanks should be operating maximally in terms of microbial
function. The work of Toonen (see above) would tend to support
this statement, as well.
The mineralization of organic matter, although dependent
on anaerobic processes, can be significant. Organic detritus
(mostly algal debris and coral mucus) is decomposed primarily
by microbial action. In an experiment using Zostera
detritus and living plants, over half the oxidation and reduction
of organic matter could be attributed to the sulfate and nitrate
reducing bacteria (Jorgenson and Fenchel 1974). Up to 80%
of dissolved organic compounds (DOC) pass through and are
absorbed by the lagoon community, and most of the particulate
organic compounds (POC) settle on the lagoon sediments (Ogden
1988). Sandy lagoons also account for more than 70% of the
nitrogen fixation in the reef (Shasar 1994). A slow downward
flux of O2 appears to be at least partly
responsible for sedimentary anoxia (Matson 1985). The end
products of anoxic decomposition are returned to near the
sediment surface, where they feed a diverse microflora involved,
once again, in primary productivity.
What are the fates of nitrate? There are many, but among
the most prominent are assimilation by algae and bacteria,
and dissimilation by bacteria (reviewed in Herbert 1999; also
see the online
review by Lomstein and its associated references). The
upper oxic layers of bacteria oxidize organics to CO2
that can be used by algae or corals for calcification and/or
respiration (Skyring 1985). The anaerobic fermenters and denitrifiers
oxidize organics to CO2 and convert
nitrate to ammonia and dinitrogen gas N2.
Terrestrial and estuarine muds have higher rates of dissimilatory
nitrate reduction back to ammonia (and not nitrogen gas),
thereby conserving nitrogen in the system for use by photosynthesizing
organisms within the sediments (Kim, et al. 1997 and
also see associated references). This is also gaining acceptance
as the primary mode of action in marine sediments, as well.
In the reduction of nitrate to nitrogen gas, nitrogen is simply
removed from the system by release into the environment. There
is a low pH in most anoxic sediments, and therefore carbon
dioxide (CO2), and organic acids produced
by the N2 community may then be shunted
to sulfide reduction and methanogenesis only if anoxic conditions
exist. The degree to which anoxia exists in tanks is not known,
and even deep sand beds may have limited conditions of anoxia
within the porewater spaces. These sulfide and methanogenesis
groups, living with redox levels as low as -450 mV, probably
exist in aquaria. In general, redox levels lower than -200mV
indicate that the beneficial reduction processes are taking
Bottom sediments and their accompanying flora and fauna are
among the most important ways of recycling organic reef material
(Sorokin 1981). The coral reef and its adjacent communities
are very effective in absorbing nutrients and recycling them
within the community, preventing loss of such energy sources
back to the ocean, and therefore allowing the vast complex
web of species to exist (Crossland and Barnes 1983). They
are largely dependent upon each other. Kinsey (1985) states
that, "gross production and calcification in coral reefs
are, nevertheless, clearly dominated by benthic processes."
From the preceding information, it should be obvious that
an effective sediment in terms of decomposing and denitrifying
ability is one that is high in organic material that supports
copious microbial populations. However, such rich benthos
also support communities of meiofauna, macrofauna and flora.
Primary deposit feeding macroinfauna of lagoonal systems include
the sea cucumbers, gastropods (Tellina sp., Rhinoclavis
sp., Strombus sp., etc.), bivalves, echinoderms, and
certain fish such as the tommyfish (Limnichthys sp.)
and gobies (Amblyeleotris sp.)(Ogden 1988).
One particular animal that has been found repeatedly to dramatically
influence the productivity of lagoonal sediments is the thallasinid
shrimp (Callianassa sp.). These shrimp, which burrow
into the sand and create small mounds of substrate around
their burrows, are both prolific and efficient. Thallasinids
are very effective "substrate sifters," and they
significantly reduce the micro- and meiofaunal populations.
"(Callianassa) play a major role in the restructuring
and functioning of lower trophic groups in lagoonal sediments."
(Hansen, et. al. 1987, Johnstone 1990). The meiofaunal
consumers such as protozoans, ciliates, nematodes, copepods,
turbellarians, polychaetes, and annelids also scavenge the
sediments for detritus, algal remains, and may even forage
on bacteria directly. Many macroalgae may be present that
vie for the rich organic content of lagoonal sediments. The
most competitive are members of the genera Microdictyon
and Caulerpa. Caulerpa may significantly uptake
ammonia produced from microbial action via their rhizoids
(Williams 1985). Microbial sedimentary populations include
viruses, bacteria, fungi, actinomycetes, molds, yeasts, and
In general, bioturbation and competition negatively affect
microbial populations. Therefore, the overall effectiveness
of sediments in nutrient regeneration is somewhat reduced
in the presence of other biota over what would be present
through the actions of microbes alone. It is interesting that
many proponents of "live sand beds" still recommend
the use of "substrate sifting" organisms such as
sea cucumbers, sleeper gobies (Valencienna sp.) and
other burrowing animals. Such bioturbation does mix the upper
layers of the sand and, in effect, cleans it of organic material.
However, they also remove substrate for microbes, change the
oxygen composition of the sand, and alter resident bacterial
populations. Keeping the sand "clean" should not
be considered a priority given the immense capabilities of
the microbes and associated organisms.
"The most exciting phrase to hear in science, the
one that heralds new discoveries, is not 'Eureka!' (I found
it!) but 'That's funny...' " - Isaac Asimov (1920
Lesson Learned: Yesterday
Thin strips of duct tape work reasonably well to attach
coral cuttings to substrate when one is without other
Putting It All Together
"Technology is the knack of so arranging the world
that we do not experience it." - Frisch, Max (1911-)
I was recently talking
with a well-known aquarist who was trying to convince me of
the need to use phosphate removing compounds and apparatus
to have a really successful reef aquarium. His points were
well taken - low phosphate levels do seem to be an important
aspect of a successful tank. But, I explained, I did not have
a phosphate problem, and haven't for many, many years. He
suggested that it must be because I don't feed much, or that
I had few fish, or that I did a lot of water changes. No,
No, and No. Perhaps I didn't stock the levels of fish that
some people do? True. I feel that if fish cannot exist in
captivity in a reasonable facsimile of their environment that
allows them to display relatively normal behaviors, I don't
like keeping them (although I admit that I do have quite a
number of fish for various reasons that fit into the unnatural
category. But, even the ones I purchased and chose on my own
to keep are old and from my earlier more exuberant days and
they will stay with me until the end of their lifespan). I
also don't find tanks crammed wall-to-wall with fish very
attractive or desirable. But, I think twenty fish in my tank
is plenty, and far over what would be found in an equivalent
space on the reef. Questions arose about my nutrient export
devices. Apparently, my skimmer was somewhat inadequate, too.
How could I have such low nutrients?
Well, for years, and despite good coral growth, I didn't
have such low nutrients, and I regularly found my nitrates
in the 5-10ppm range, and phosphates around 0.1ppm as measured
at the time by hobby test kits. This was during the time when
I ran a "Berlin system." My nutrients dropped to
immeasurable levels when I added a sand bed, and they have
remained that way ever since.
I would offer a few suggestions to those troubled by certain
If the tank has low measurable nutrient levels, and
low particulates in the water column, add food.
Bacterioplankton in tanks as a trophic source may not
be the ideal area to address. Plenty of bacteria become
waterborne each time the glass is cleaned, each time
a crustacean or fish or snail moves through the sand,
each time a fish poops or swims through the water releasing
mucus from their skin, as corals release mucus, as organisms
bore into substrate, and they probably bloom briefly
and transiently with food additions. In addition, corals
have huge microbial populations on their surfaces and
in their gastric cavity, and a ciliated epidermis. Need
I say more?
Sand beds are not nutrient traps unless seriously mismanaged,
in which case the problem is with the aquarist and not
the sand. If mismanaged and a chronic problem, simply
yell "do-over" and fix the problem and not
repeat the problematic behaviors that initiated it in
the first place. The sediment communities and associated
microbial communities are the major source of nutrient
processing, decomposition, recycling, and remineralization
in the wild, and likely in tanks, as well.
If a tank has high nutrients in the water column, a
hose, bucket of water, and bag of salt cures it. It
is cheap and works every time. There will be no heated
debate as to the efficacy or downsides of its effectiveness.
There is no regular maintenance required, no replacement
of media, and no "experimentation" required.
When coupled with two containers, a small powerhead,
some more hose, and a timer, automated water change
apparatus can be accomplished for about $20-50, depending
on the size of the containers. Future water changes
will cost exactly as much as the salt and water required
to fill the input container. No worries about diseases,
blooms, oxygen drops, media replacement, leaching, or
anything else. For the fifteen years since I started
keeping reef aquaria, the reluctance of most aquarists
to do water changes, but willingness to invest extraordinary
and often frustrating amounts of time, money and effort
into products, techniques, and equipment to avoid a
simple procedure has baffled me. If you don't have the
time or inclination to make up seawater and do a water
change, you probably don't need to be keeping marine
animals as a hobby.
Nutrients in aquaria are not just a matter of input
and export. Uptake is significant. Calcium levels, normally
at 400-450ppm, are taken up by my tank at a rate that
I must replace the calcium every two days, and I try
to do it daily. The same is true of alkalinity. Almost
every organism kept in aquariums, and assuredly the
lion's share in terms of biomass, can either directly
take up dissolved and particulate material, or be involved
directly or indirectly in decomposition pathways. The
uptake of nitrogen and phosphorus directly and incorporation
into biomass by growth and reproduction should not even
raise an eyebrow in terms of the orders of magnitude
less of these substances that exist. If my coralline
algae, snails, corals and mollusks can produce enough
skeletal material to remove 30ppm of calcium per day
from my tank, I would hope they and every other non-calcifying
organism in my tank is growing or reproducing enough
to take up immeasurable levels of nitrogen and phosphorus
and put it into tissue growth. If they aren't, I'm doing
a bad job at growing things.
Plants require fertilizer regularly because
they grow. Terrestrial animals require food to grow. Why,
exactly, do we think that the same doesn't hold true for aquariums
packed with life? If I feed a certain amount of food to my
tank, and obviously there is no food in the water moments
or even hours later, the only thing left is secondary production;
wastes and excreted material are all that's left to feed the
huge array of creatures in the tank that did not happen to
capture anything directly, and that ain't much. But it works,
just like it does on the reef. The recycling of nutrients
given the diversity in reef aquaria is exactly the same as
on coral reefs in terms of the processes involved. True, we
lack the dilution effect of the ocean water, but coral reefs
don't have skimmers, either. Furthermore, the increased "bioload"
of consumers is also matched by an increased "bioload"
of producers (corals, algae, etc.). While unmeasured, it would
be a virtually impossible biological situation to not see
a similarly increased "bioload" of microbial communities,
as well. I am, therefore, as concerned as ever that despite
everything, one of the primary limitations of my tank (and
most tanks) is how to provide enough food. If we can accomplish
this, perhaps the survival of azooxanthellate species we long
to keep will be made possible. These are the questions to
ask and the problems to surmount.
Can we add more food if we reduce nitrates
by adding vodka? Why vodka? Why not sugar? And if sugar, why
not more photosynthetic organisms to produce the sugar? And
why not more corals to produce polysaccharide rich mucus?
Would adding more corals reduce nitrate? Actually, they would
and they do. A long time ago, when Steve Tyree had promoted
the use of sponges for natural filtration, I suggested corals
would accomplish the same purpose. Coral filtration
that's really up my alley!
"All truly wise thoughts have been
thoughts already thousands of times; but to make them truly
ours, we must think them over again honestly, till they take
root in our personal experience." - Johann Wolfgang
von Goethe (1749 - 1832).
"We may define "faith"
as a firm belief in something for which there is not evidence
... Where there is evidence, no one speaks of "faith".
We only speak of faith when we wish to substitute emotion
for evidence." - Bertrand Russell, 1955.
may be surprising to learn that a great portion of the information
written above came from an article written in 1998 by some
guys named Eric Borneman and Jonathan Lowrie, and appeared
in the June issue of Freshwater and Marine Aquarium
magazine. If one looks at the references, much of the information
on carbon, nitrogen and phosphorus dynamics was well known
in the 1970s and 1980s, with many direct studies on coral
reefs. Now, I may not know much, but I do know that in the
twenty or so years that we have been keeping corals alive,
it has become obvious that the apparatus that was so heavily
depended upon in the early years to simply maintain corals,
such as denitrators, bioballs, phosphate removal media, and
others, is no longer required. John Tullock (1997) stated
eloquently that we needed "more biology and less technology."
Those words have come true to a great extent, and concurrent
with better technology. The result is that we now have reef
tanks easily capable of being maintained with immeasurable
levels of phosphate and nitrates, our corals show outstanding
growth and coloration to the point where many of us are searching
for places to rid ourselves of excess growth of some species,
and corals literally grow out of the tank. Such aquaria are
regularly featured as the tank-of-the-month in this magazine.
Removing functional natural processes and replacing them with
experimental methods and apparatus seems to me like a bad
idea. It didn't work very well in the 80s, and I don't think
it will work well today, either.
I consider "long-term" in aquariums
to be on the order of years. The debates being mentioned above
have occurred within the past year, and already fierce proponents
extol the relative benefits and detriments of one way or the
other. My view is that time and adequate experimentation and
measurement will tell the tale. To me, having a 6" deep
sand bed for eight years with no measurable nitrate or phosphate
and no regular or intentional water changes says something.
I have outstanding coral growth and great coloration. In fact,
my tank has never looked better. I'm keeping the vodka for
"I dreamed a thousand new paths
. . . I woke and walked my old one." - Chinese proverb.