One person stated that they change their water because they enjoy it.

...but they didn't say that they changed their water _only_ because they
enjoy it.

Really? Are you sure about that?

This person changes their water because they "enjoy" doing it:
http://tinyurl.com/y9xveh

Do I think this is absurd? No. But it demonstrates a lack of
understanding. AND it is in line with the "herd behavior".

I'd give you a link, but Google Groups archive is currently
down. IIRC, that was a comment from Rock, in that "what to do with used
marine water changes" thread, right..?

Nitrogen cycle unsound? Your kidding me right? The nitrogen cycle
AND denitrification are the reasons behind NOT having to do water
changes.


Don't be obtuse.

I'm being obtuse? Ah, lets resort to insults.

I was of course referring to Wayne's article at his site,
and its reflection on _his_ grasp of the nitrogen cycle.

His "grasp" of the nitrogen cycle? He doesn't even now what ammonia or
nitrite. How could he possibly understand the nitrogen cycle when he
doesn't even understand the basics?

Also, you replied without saying anything to support your assertion that
the forum users here 1) are changing water because everybody else is, and
2) that they lack sufficient understanding of the chemical and biological
processes in their aquaria. Again, what has convinced you of that?

This newsgroup.

My tank size is a qualification for NWC? How? My tank size provides
quantification for NWC? Please explain.


Don't be obtuse.

Ok, attack me. Shall I throw a few snotty remarks in your direction? (see
below)

I'm asking for (and slowly getting) the context under
which you've obtained your claimed success, because without it, your
claims
are less than useful.

Of course "my claims" are useless to you unless you apply what I have done
in your aquarium.

Word games such as these do not paint you in a
favorable light.

I am playing "word games" ?

You asked me an obtuse question and I answer it. This means I am playing
word games OR does it mean your question was ridiculous to begin with?

To answer your inane response, of course tank size alone
doesn't qualify or quantify NWC.

You asked for "Qualification for, and quantification of, the information you
offer." Remember?

If tank size doesn't matter than why did you ask the question? And how is
my response to your question inane? I answered your question.
If you don't want inane answers stop asking inane questions!

Not necessary IMHO.


Chaeto growth is one of the main differences between yours and
blackhole's tank (yours is a FOWLR his is reef).

I now have a pulsing xenia (new edition last weekend)

Does this qualify as a reef tank now?

NWC reef tanks are few
and far between,

Really? I think we have been here before too! (CIRCLES) How many NWC reef
tank owners have you polled? What background do they have? Are they
college educated? What age bracket do the people fall in that you polled?
Do they have a background in science? How long have they had their tank
running? Of the people you polled, how many failed with NWC ? Did they
vote for Bush? Seriously, I think you are being a little obtuse with
that statement.


(IY and blakchole's are the only two I'm aware of),

What does this mean? This is your most obtuse statement yet.

one would think that a genuinely curious person would like to know more
about
it, before they decided if its necessary or not.

Or they could just try it both ways and realize WC's are not necessary.

If my waste exceeded the metabolic capabilities of my bacterial load
than wouldn't my ammonia or nitrite or nitrate demonstrate this? As I
stated already, they are all 0ppm (LFS test kits).


I don't undestand what the big deal is, here? We all know that a Yellow
Tang places less demand on a tank than a Spanish Hogfish. I'm just trying
to get a better idea of what sort of bacterial demand your fish place upon
your NWC system.

Why is this relevant? If you truly understood the nitrogen cycle and
denitrification you wouldn't be asking this question. ANSWER: If my
bioload was in excess of my bacterial metabolic capabilities, wouldn't my
water tests signify this? AGAIN, bacteria fluctuate in population directly
with their metobolic "food" source. More "food" and they grow in number (in
general). Why are you having trouble with this?

You said you had a background in chemistry, but it appears I still need to
simplify things for you.
Water changes decrease your bioload therefore bacterial cell count drops
accordingly. You take away their "food" and their is less "food" to go
around. Some cells will starve and dye off. The remaining cells will
continue to metabolize nutrients (NH3/NH4, NO2-, NO3-).

Every time you do a water change you are removing their "food".


I stated already that my fish appear healthy. Why do you insist on
taking this discussion in circles?


Its more a back and forth straight line, really ;-). I ask for more
information on the circumstances under which you've acheived success, and
you keep deflecting the questions

Am I deflecting questions OR are you incapable of comprehending the answers?
My only fault is not over simplifying things from the beginning.

(actually, you selectively answer a few
with each successive post, and deflect others. Maybe in a few more rounds
of this, we might have a full picture of whats going on in your tank,
without, ya know, actually having a picture .
Healthy fish in a FOWLR system does not necessarily equate to adequate
water quality for the more sensitive corals,

Really? You are being VERY naive in suggesting that "sensitive corals"
would do any better in a WC tank than my NWC tank. Which of my water
parameters that I have provided you so far do you think would hinder the
health of "sensitive coral"? Was it my 0ppm Nitrate? OR my 0ppm nitrite? OR
my 0ppm NH3/NH4? Or my addition of Kent Marine Essential Elements?

New values for you:
OR is it my pH which is 8.1-8.2? Or is it my salinity which is 1.024? Or
is it my lighting which is 4 110watt VHO's?

BTW. If you haven't tested
your water recently, who's to know whether your nitrates are up, and your
fish and anemone just don't show it, because its been developing slowly
since your last test? Add some acropora

I test once a month. All fine. You really seem to be having a problem
grasping what those little bacteria are doing in your tank. I suggest
reading about the "nitrogen cycle" and the process of dentrification which
involve anaerobic bacteria.

Not only am I convinced that most in this NG don't understand the above (N2
cycle and denitrification), I am NOT convinced YOU understand based on your
questions.

This is why MOST do water changes. Because they DON'T understand at the
biological level why it is NOT necessary.

MOST think that the ONLY way waste is removed from their aquarium is by
doing water changes. This is a HUGE fallacy! Protein from excess food and
fish waste is degraded/metabolized by proteases present in organisms in the
aquarium (some crustaceans in your aquarium contain proteases). NH4/NH3
fish waste and a product of protein metabolism is taken care of
(metabolized) by bacteria.

YOU are being VERY naive if you think most in this NG understand the above.

Read above about ammonia, nitrate and nitrite. Again, I am getting
the impression that you are taking this discussion in circles.


You have done little to quantify the bio load of your tank, so I'll just
keep asking. Circles aren't inherently bad, especially since you're
offering a little more with each "turn". Don't like circles? Simple...
Then don't bother to reply (always an option), or reply in full.

Read above about bioload and bacterial cell count. (wanna go around again?)

I don't remember the total pounds. I use to buy a little at a time.
I didn't keep track. Sorry. Sand is roughly 2-3 inches.

NP. I'll bet you could offer a ball-park number if you tried... Also,
what kind of rock is it? Florida aquacultured is quite different, pound
for pound, than Marshall Island or Tonga rock.

Why does this matter if my bioload is under control? If you are simply
trying to repeat my success than I guess I should ask you how much you have?

1-hermit crab. A few snails.

Pretty small crew, for a 75gal...

Why do you say this? What information have I given you to make you come to
this conclusion? Was it my excellent water parameters?

Again. I am pretty sure we have been through this already. Ammonia
--- nitrite----nitrate----N2(g) + H2O. (Enzymatic conditions via
bacteria.)


That's it? That's what you think people here _don't_ grasp? Good grief,
bo0ger, _everyone_ with a reef tank understands at least that much of the
nitrogen cycle.

You make me chuckle Sir! That is a VERY naive statement. Your line of
questioning casts serious doubt about your understanding of it.

They go a little further, though, and also take account of the fact that
there is a maximum possible population of bacteria for a given tank setup,

Sure there is. This is why it is possible to over stock an aquarium with
inhabitants. NOT the reason to do a WC.

Want to lower your bacteria cell count even further? Increase the
percentage of water you change. What do you think would happen to your
bacterial cell count if you hypothetically changed ALL of your water with
every WC?

a relationship between fish species/mass and the amount of waste
generated,
and differences in final water quality depending upon the details of the
above, and that certain aquatic species (especially corals) are intolerant
of less-than-perfect water quality.

Which of my water parameters are "less-than-perfect"?

Doing water changes guarantees "perfect" water?

No, it implies that those that do water changes don't know why they do
them. If they knew what was going on at the biological level (see
above), they would know why it isn't necessary.


But they apparently know everything that you do, and maybe some things you
don't.

Like what? Elaborate on this please.

And really, you haven't shown them to be "unnecessary".

You haven't shown that they are "necessary". Nor has anyone else.

What you've suggested is that Kent Marine Essentials can supplant/replace
their
necessity in a FOWLR system of some unquantified setup. Blackhole has a
similar method for a reef setup, which adds a nurtrient export method
(that you discount without elaboration),

I haven't described my nutrient export method? Re-read above (HINT:
bacteria).

which also seems to be doing well. How you leap from there, to wild
speculation into the also successful
methods of others is beyond me. I see no evidence that the people who
post
here are somehow deficient in chemical or biological knowledge,

You are demonstrating it in this thread Sir.

especiall knowledge as fundamental to the hobby as the above. Their reef
tanks'
success are clear proof of that.

My experience tells me that there is an upper limit to the load you
can place upon the bacterial colony in a tank.

How many experiments have you performed?

I've maintained five different marine setups by this point in time, each
one a serial replacement for the previous setup. My current (5th) setup
is
a reef-type (but with species less sensitive to water quality. Its a 50
gal tridacnid tank; 4 crocea and a derasa, all small, with a few assorted
corals (an open brain, small green mat zoanthids, a mushroom leather
coral), a Clown Wrasse, and a pair of Banggai Cardinalfish, (under)skimmed
with a CPR Backpak, 50 lbs of Fiji LR, a 4 inch deep Aragonite sand bed
which is old enough to be well-seeded with bacteria, a 15 gallon sump, no
nutrient export method, a pair of 100W MH pendant lamps, a pair of
powerheads. Team Detrivore is comprised of nine hermits and a dozen
snails, there is also a lawnmower blenny in there to stir up the substrate
a bit more.
I replace tank evaporate with kalkwasser to keep the calcium in line, and
I change about 5% water weekly, without any additional supplements. Its
had its current configuration for 5-6 months, with 0/0/5 mg/L of NH4
+/NO2-/NO3- as average results, measured weekly. I also test weekly for
specific gravity, pH, and calcium along with a monthly iodine /iodide
test.
If iodine/iodide is low, I raise the % water change to 10% for the next
week, and re-test. That's always seemed to work. I had one spike up to
15
mg/L NO3- , when i added the clams (had to add all 5 at once), but
mitigated that with extra water changes (5% daily until the bacteria could
catch up) and by running the skimmer a little drier. I seem to be looking
good for now, as growth of all occupants is measurable. Gee, offering
that
context to my experience was absurdly easy...

That was your experiment for this:
"My experience tells me that there is an upper limit to the load you can
place upon the bacterial colony in a tank."

What you described weakly qualifies as an experiment. How does your
"experiment" quantify bioload? When do you address and quantify the
"limit"?
Where do you mention your control tank with NO water changes? And what was
the "upper limit" of bioload that you placed on your bacteria in your
control tank?
What was the "upper limit" of bioload that you placed on your bacteria in
your WC tank?

Re-read that link you referenced about the Scientific Method. (read the part
about a 'control')
http://en.wikipedia.org:80/wiki/Scientific_method

How many conditions have you varied?
Different fish, different bio loads, mostly the same live rock (I like my
Fiji rock, its got high porosity for its weight, and I think that gives me
a better living filter). I'd be happy to chronicle the past experiences,
but that would be more appropriate for a different thread. The conclusion
of them is that, the need for water changes and their degree varies, based
on occupancy and the water quality demands of the specific species.

Is this anecdotal data?

It sure is. There's nothing wrong with that, per se, so long as any
readers value such information appropriately, and so long as I don't get a
swelled head, or start ragging on others for acheiving success
differently...

Why is my/others NWC anecdotal data less valid?

Lets NOT go in circles anymore. I have presented my case ad nauseam.


Yeah, I was hoping to get into the details of your system more, but you
seem less than enthusiastic at this point. OK by me.

No. I think your only intention was to try and invalidate my findings in
some way. But I do understand your reasoning to do so.

Take care.



DaveZ
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