"bo0ger1" .@. wrote in
:

Do you know why I refer to it as the 'herd mentality' or 'herd
behavior'? Because most people in this forum (and most people that I
have discussed the topic with) perform water changes ONLY because
everyone else is doing it.

Really? What has convinced you of that? Thus far, the only thing
I've seen to that end is that you've cited errors at Wayne's site wrt
valence state and number of oxygens on nitrite, nitrate, and ammonia.
Despite those errors,

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. 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..?

did you also find the underlying theory of the nitrogen cycle
to be somehow un-sound?

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 was of course referring to Wayne's article at his site,
and its reflection on _his_ grasp of the nitrogen cycle. Was there
something in the article, other than a few errors of valence state and
number of oxygens, which demonstrated a lack of understanding of the
nitrogen cycle?

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?

Not evidence, but context. Qualification for, and quantification of,
the information you offer.

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


Don't be obtuse. 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. Word games such as these do not paint you in a
favorable light. To answer your inane response, of course tank size alone
doesn't qualify or quantify NWC.

http://www.reefland.com/rho/0105/main2.php

1/2 way through that article, you'll find a pic and discussion about
the Chaetomorpha that blackhole is using to export nutrients.

Not necessary IMHO.


Chaeto growth is one of the main differences between yours and
blackhole's tank (yours is a FOWLR his is reef). NWC reef tanks are few
and far between, (IY and blakchole's are the only two I'm aware of), one
would think that a genuinely curious person would like to know more about
it, before they decided if its necessary or not.

fish species/size? (I'm not sure how this qualifies as evidence)

It quantifies the fish mass (and the corresponding amount of waste)
which can be handled without the need for water changes as a means of
nutrient export.

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.


inverts species/size? (I'm not sure how this qualifies as evidence)

It identifies whether or not the species you are keeping are
relatively robust, or prone to problems related to less-than-perfect
water quality (as, ofr example, some SPS corals are famous for).

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 (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, 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

Lights and powerheads go towards general suitability of comparing
your
results to those of a reef system with inverts. If, for example, you
only maintain flourescent lights for observing your fish, then you
might expect that low light is also helping to control your rate of
algae growth. With some SPS reef systems running 4-6 Watts/gallon of
broad spectrum Metal Halide lighting, smaller changes in water
quality become larger problems with algae growth, as the algae has
all the light it needs to grow prolifically.

Feeding schedule? (I'm not sure how this qualifies as evidence)

As with fish mass, it helps to understand how much of a nutrient load
your system is handling, without the need for water changes.

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.

My inhabitants appear healthy. I am certain that they would not
appear unhealthy to you.

NP. Forget the picture. I'll take your word that all of your
occupants are healthy and happy.

Oh, Man! Did I forget two BIG ones!

How much live rock (pounds), and/or live sand in your system(depth in
inches)? What kind of live rock (point of origin)?

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.


What does your detrivore cleanup squad look like (hermits, snails,
sandsifters, etc)?

1-hermit crab. A few snails.

Pretty small crew, for a 75gal...

That's what makes this thread so sad. If you understood why water
changes were not needed (at the biological level) you would
understand how really simple (not rocket science) this topic is.

Please expand on this idea. I want to understand, at the biological
level,
why water changes are not needed. Take me through it, step by step,
please.

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.
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,
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.

The latter implies that the way in which you transition
from WC to NWC requires some education into chemistry/biology before
doing so, and thus NWC may _not_ be as simple as the first quote
implies.

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. And really, you haven't shown them to be "unnecessary". 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), 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, especiall
knowledge as fundamental to the hobby as the above. Their reef tanks'
success are clear proof of that.


I think you are right about water changes, to a certain extent, but
i'm a bit more cautious about which setups I would consider NWC
for, especially reef type setups.

My experience has directed me to the following conclusion (again,
take it or leave it): Water changes weaken your bioload. Bacteria
exist in your aquarium that take care of ammonia, nitrite AND
nitrate. The end result is N2(g) and H2O. I would suggest stopping
your water changes gradually (gauge by testing) to allow your
bacteria to proliferate.


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...

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...

A little hypocritical eh?

Hypocritical would be if I was elusive about the circumstances for my
success, assumed that others who do things differently do so because
they're ignorant, and/or postured as if my limited experience is worth more
to this community than it actually is.

I accept that NWC change systems are reasonable and certainly
possible, but I suspect that you need
to start (and possibly maintain) them on the low end of the total
load to a
tank's bacterial colony. At this point in time, I'm trying to get a
feel for where your tank fits into the range of possible bio-loads.

BTW, I've usually seen the term "bio-load" as an expression of the
amount of vertebrates/invertebrates vs. tank/system size.

Bioload is directly proportional (in general) to the bacterial
population. Increase bioload, and increase bacterial population
(proliferation). Decrease bioload and you will decrease bacterial
population (again, this is a generality).

OK, you use "bioload" as a polite term for "fish-poo in the water column".

So, when I state that "Water changes weaken your bioload", this is
what I am referring to. Water changes lower bioload thus lower your
bacterial population (less to metabolize = bacteria cell count drops).


Thanks. Not what I've seen it used as before, but now I understand your
comments.

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.

DaveZ
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