Nitrate
Contents:
- Amount of Nitrite vs Nitrate
by booth-at-hplvec.LVLD.HP.COM (George Booth) (Mon, 3 May 1993)
- Freshwater Nitrate Levels
by oleg-at-netcom.com (Oleg Kiselev) (Sat, 18 Dec 1993)
- Good NitrAte test kit??
by hardy-at-mighty.fccc.edu (Richard R. Hardy) (Mon, 29 Aug 1994)
- Good NitrAte test kit??
by hardy-at-mighty.fccc.edu (Richard R. Hardy) (Tue, 30 Aug 1994)
- Another denitrator crash-and-burn!
by eethomp-at-welchlink.welch.jhu.edu (ELAINE THOMPSON ) (8 Dec 1994)
- FAQ update: how do test kits work
by patbob-at-sequent.com (Patrick White) (Mon, 16 Jan 95)
- FAQ update: how do test kits work
by cb77-at-namaste.cc.columbia.edu (Craig Bingman) (20 Jan 1995)
- Nitric & Sulfuric acid
by George Booth <booth/hpmtlgb1.lvld.hp.com> (Fri, 07 Feb 1997)
- Nitrate factories are stupid.
by charleyb/gr.hp.com (Charley Bay (Contract)) (Thu, 28 Sep 1995)
- (M) Kordon Test Kit Problem
by rclark/alcor.concordia.ca (Richard Clark) (3 Apr 92)
- NITRATE
by SRRapp/ccmail.monsanto.com (Stephen Rapp) (Mon, 30 Aug 1993)
- Aquatic Plants Digest V3 #1039
by Watford28/aol.com (Wed, 19 May 1999)
- Fish load .v. plant load
by "Roger S. Miller" <rgrmill/rt66.com> (Wed, 19 Jan 2000)
by booth-at-hplvec.LVLD.HP.COM (George Booth)
Date: Mon, 3 May 1993
Here are some details on nitrification and denitrification.
From:
Water Chemistry in Closed System Aquariums
Alfred J. Gianascol, 1987
By the way, this is from a two volume set produced by Dr. Gianascol.
This is an incredible reference with just about all the water chemistry
info you ever need to know. He has performed controlled experiments
in all phases of aquaculture and the results of those experiments
address many of the questions that are posed on the net that "there
are no answers for". They are pricey, $35 each, but extremely well
worth it. I saw the first volume advertised in the back of FAMA a
few years ago and got the second volume through an update mailing
by Dr. Gianasol.
They are probably still available since they are photocopied and
spiral bound. 160 pages total. Write to:
Alfred J. Gianascol, M.D.
1077 Cass Street, Suite D
Monterey, CA 93940
-----------------------------------------------------------------
Prior to nitrification, ammonification of protein occurs as follows
using an emprical formula for algal protoplasm:
C H O N P + 118 O --> 106 CO + 65 H O + 16 NH + H PO
106 181 45 16 2 2 2 3 3 4
Sulfur is omitted because of its low concentration. Note the production
of both ammonia and phosphate.
Nitrification follows. C H NO represents the composition of nitrifying
bacteria. 5 7 2
+ -
(NH ) + 1.83 O + 1.98 (HCO ) -->
4 2 3
-
0.021 C H NO + 1.041 H O + 0.98 (NO ) + 1.88 H CO
5 7 2 2 3 2 3
Omiting the negligible effect of the growth of the bacteria:
+ - -
(NH ) + 2 O + 2 (HCO ) --> (NO ) + H CO + H O
4 2 3 3 2 3 2
Essentially, nitrification has the same effect as titrating water with
nitric acid (bicarbonate is used up and nitrate is generated).
-------------------------------------------------------
Denitrification:
This requires an organic carbon source such as methanol, but the
organics in the water from carbohydrate and fat decomposition may
serve as the carbon source.
-
(NO ) + 1.08 CH OH + 0.24 H CO -->
3 3 2 3
-
0.056 C H NO + 0.47 N + 1.68 H O + 0.056 (HCO )
5 7 2 2 2 3
Omitting bacterial synthesis:
- -
(NO ) + 0.833 CH OH + 0.167 H CO --> 0.5 N + 1.33 H O + (HCO )
3 3 2 3 2 2 3
Note that in nitrification, nearly 2 mEq of bicarbonate are consumed
as 1 mEq of ammonium is oxidized to 1 mEq of nitrate while in
nitrification, only 1 mEq of bicarbonate is produced by reducing 1 mEq
of nitrate. On balance, a progressive loss of alkali and an increase
in carbon dioxide will result unless some means are taken to correct
this.
------------
George
by oleg-at-netcom.com (Oleg Kiselev)
Date: Sat, 18 Dec 1993
Newsgroup: rec.aquaria
In article <1993Dec17.193152.557-at-icd.ab.com> dav-at-icd.ab.com (David A. Vasko) writes:
>What are optimum fresh water nitrate levels for >freshwater planted tanks ?
If your tank is "working" then the levels will be below the usual testkits'
sensitivity.
>What is acceptable ?
Less than 10-20 ppm. Acccording to Scheurmann most aquatic plants start
needing a lot more light to pbe able to photosynthesize in high nitrates
environment. Some plants (Water Hyacinth, Bacopa, duckweed) do well in high
nitrate environment.
>What level will start to cause problems ?
Fish exhibit severe nitrate stress when the nitrates levels get to 60 ppm.
Plants fail before then.
--
Oleg Kiselev at home ...use the header to find the path
by hardy-at-mighty.fccc.edu (Richard R. Hardy)
Date: Mon, 29 Aug 1994
Newsgroup: rec.aquaria
In article <1994Aug28.073845.21502-at-lmpsbbs.comm.mot.com>,
gordonb-at-mcil.comm.mot.com (Gordon Berkley) wrote:
> The subject says most of it. I am looking for recommendations on a
> good (not great, my budget and requirements are limited!) Nitrate test
> kit. It is to support a 30g fish + invert tank.
>
> Due to high costs on this side of the atlantic, I will be
> mail-ordering mine. For the same reason, I can't exactly ask my local
> fish-store-guy for a recommendation :-)
>
Red Sea (from Israel!) makes a nitrate kit that shows distinct color
differences (blue vs. green) between 0 and 2.5; not ultra-sensitive, but
better than the standard kits that don't kick in before 20; also very
inexpensive here in the States.
--
R. Hardy
Member, Institute for Cancer Research,
Fox Chase Cancer Center, Philadelphia, PA
(215) 728-2463
by hardy-at-mighty.fccc.edu (Richard R. Hardy)
Date: Tue, 30 Aug 1994
Newsgroup: rec.aquaria
In article <1994Aug30.060100.19681-at-lmpsbbs.comm.mot.com>,
gordonb-at-mcil.comm.mot.com (Gordon Berkley) wrote:
> *sigh* believe it or not, the Red Sea kit is probably LESS expensive on
> your side of the super-aquarium (:-) than over here, where it is made!
> ... even AFTER the cost of shipping it both ways!
>
> If I can find it mail-orderable, I will probably end up buying it that way.
> The price here for the nitrate test kit is about $20. What does it run
> in the 'states??
>
It's $10 (100 tests) from "That Fish Place".
--
R. Hardy
Member, Institute for Cancer Research,
Fox Chase Cancer Center, Philadelphia, PA
(215) 728-2463
by eethomp-at-welchlink.welch.jhu.edu (ELAINE THOMPSON )
Date: 8 Dec 1994
Newsgroup: rec.aquaria
Well, after the DIY coil denitrator stories that George and others
(sorry...I forgot who else) posted a few months ago, I should have known
better. But, I tried installing a Nitrex box in my 29g planted tank,
thinking that maybe something that was commercially available would work.
NOT! So here's my sad story that will hopefully convince you not to try
Nitrex.
I put the gadget in at the start of October. It's an almost sealed box
with a medium that is supposed to selectively grow denitrifying bacteria
and allow only a slow flow of water through. Nitrates did drop within a
couple of weeks to below 25 ppm--the bottom of my cheap test kit. Before,
they were between 25 and 50. Great, I thought. It works, and the algae
growth has slowed to a virtual standstill.
The problem? Fish diseases. After one round of killer Ick, one round of
bacterial stop-eating-hang-out-at-the-top-and-die-in-24-hours disease, and
two rounds of Columnaris, I had had enough. Water tested fine; pH 7.0, no
ammonia, no nitrites. And all of my other tanks have been WAY healthy.
What finally convinced me to yank the Nitrex box was when I added a new
clown loach from another healthy tank and he got Columnaris too.
So, I pulled the box out of the tank. I opened it up and was greeted by a
foul rotten-egg odor. So much for the Nitrex stuff not allowing
sulfide-producing bacteria to grow. Immediately, the fish looked
healthier, and that evening my angelfish ate his first healthy sized meal
in a while. The clown loach is healing up too.
The moral is: don't try denitrification. It's not worth it. Really,
it's not.
BTW, I know there are folks laughing and saying "I told you not to add
weird stuff to your tank." Well, I will save you the trouble of posting.
I TOLD YOU SO
There. Satisfied?
--
Elaine Thompson "Two roads diverged in a wood and I,
eethomp-at-welchlink.welch.jhu.edu I took the one less travelled by,
Johns Hopkins Univ. And it has made all the difference."
--Robert Frost
by patbob-at-sequent.com (Patrick White)
Date: Mon, 16 Jan 95
Newsgroup: rec.aquaria,alt.aquaria,sci.aquaria
In article <NARTEN.95Jan12092740-at-tmp144.cs.duke.edu>,
Thomas Narten <narten-at-cs.duke.edu> wrote:
>Can someone provide an explanation (or provide pointers to) an
>explanation for how ammonia/nitrite/nitrate test kits work? What are
>the chemical reactions, and exactly what are the compounds that are
>being tested for?
I ran across this someplace and then discarded it as I didn't have the
lab, and didn't want to keep the caustics/poisons around the house. I found
it either in something by Spotte or in aquaculture literature -- I think it was
in the book Spotte wrote (cowrote?) that covered artifical seawater.. including
recipies for mixing your own artificial seawaters and tests of interest to the
scientist/aquaculturist.
>For example, is it the case that nitrate test kits actually convert
>nitrate to nitrite first, and then test for nitrite? If so, this
>could lead to extremely misleading conclusions when testing for
>"nitrates" to determine when a tank has fully cycled.
The one I has does exactly this. It's because the indicator solution
only works with the nitrite-derived result. So yes, one must technically
test for nitrites first, then subtract it. However, most of the time in
established aquaria, nitrites are nil (or very low) and can be safely be
ignored. I wonder if the nitrate->nitrite reagent would affect the indicator..
if not, might be able to add indicator to get nitrite reading, then reagent to
get nitrite + nitrate reading.
FYI, if you follow the ammonia & nitrite peaks as Moe suggests, then it
really doesn't matter.
BTW, if you read enough Spotte, you'll find that nitrite is negiglently
toxic in saltwater as the chloride ion, in the concentration present in
seawater, effectively blocks it's toxicity. I've read independent verification
of this in some aquaculture literature or another, so it seems to be true.
Technically though, the same applies towards ammonia tests -- only one
of the forms ammonia takes in water (NH3 or NH4+) is toxic. The test pushes
all of it to the form the indicator works with. If you wanted to be technical,
you would look up in a table the actual amount of toxic form given the total
concentration and the pH. However, since pH shifts day/night, and even hour to
hour, it's safest to assume all of it is in the toxic form and act accordingly.
--
Pat White (work: patbob-at-sequent.com, (503) 578-3463)
hang 2
by cb77-at-namaste.cc.columbia.edu (Craig Bingman)
Date: 20 Jan 1995
Newsgroup: rec.aquaria,alt.aquaria,sci.aquaria
In article <NARTEN.95Jan12092740-at-tmp144.cs.duke.edu>,
Thomas Narten <narten-at-cs.duke.edu> wrote:
>Can someone provide an explanation (or provide pointers to) an
>explanation for how ammonia/nitrite/nitrate test kits work? What are
>the chemical reactions, and exactly what are the compounds that are
>being tested for?
I'd refer you to the Hach water analysis handbook for a very detailed
account of the chemistry that Hach uses. It isn't universal, though,
for example, several aquarium test kits use hydrazine in the nitrate
test kits (as a reductant, in place of the cadmium that Hach uses,
I believe.) If you want the ultimate skinny on water testing, send
people to Standard Methods. Spotte has a number of methods in
his 1992 book subtitled "Science and Technology"
>For example, is it the case that nitrate test kits actually convert
>nitrate to nitrite first, and then test for nitrite? If so, this
>could lead to extremely misleading conclusions when testing for
>"nitrates" to determine when a tank has fully cycled.
Yes, that is exactly what they do, and I've made exactly that point
here a couple of times. You can't test for nitrate to show that
an aquarium has cycled, because all of the hobby nitrate tests
actually indicate (NO3+NO2) leaving the charges off the ions for
clarity. One can determine the actual nitrate concentration by
running a nitrite test as well, then subtracting the observed nitrite
from (NO3+NO2). There are methods of detecting nitrate directly,
but they are not cost effective for home aquaria.
I'll write a blurb for you about each test you want covered. Just tell
me what you need.
Craig
by George Booth <booth/hpmtlgb1.lvld.hp.com>
Date: Fri, 07 Feb 1997
> From: spush-at-saudan.HAC.COM
> Date: Thu, 06 Feb 1997 16:25:04 PST
>
> I was wondering if nitric acid is a biproduct of the nitrification
> cycle or other chemical processes in the aquarium?
Yes, the nitrification process is equivalent to titrating with nitric
acid. The result is hydrogen ions (H+) and nitrate (NO3--) (and other
stuff, of course). Carbonate hardness is slowly used up in the
process, reducing buffering and pH. When the KH is completely
depleted, you will find that the pH will stabilize around pH 4.4
(given typical natural conditions).
Here's the chemistry involved (not precise, but good enough for a
general discussion; I've been told there are a few electrons missing
here and there).
| From:
| Water Chemistry in Closed System Aquariums
| Alfred J. Gianascol, 1987
|
| -----------------------------------------------------------------
| Prior to nitrification, ammonification of protein occurs as follows
| using an emprical formula for algal protoplasm:
|
| C H O N P + 118 O --> 106 CO + 65 H O + 16 NH + H PO
| 106 181 45 16 2 2 2 3 3 4
|
| Sulfur is omitted because of its low concentration. Note the production
| of both ammonia and phosphate.
|
| Nitrification follows. C H NO represents the composition of nitrifying
| bacteria. 5 7 2
|
| + -
| (NH ) + 1.83 O + 1.98 (HCO ) -->
| 4 2 3
| -
| -
| 0.021 C H NO + 1.041 H O + 0.98 (NO ) + 1.88 H CO
| 5 7 2 2 3 2 3
|
|
| Omiting the negligible effect of the growth of the bacteria:
|
| + - -
| (NH ) + 2 O + 2 (HCO ) --> (NO ) + H CO + H O
| 4 2 3 3 2 3 2
|
| Essentially, nitrification has the same effect as titrating water with
| nitric acid (bicarbonate is used up and nitrate is generated).
|
| -------------------------------------------------------
| Denitrification:
|
| This requires an organic carbon source such as methanol, but the
| organics in the water from carbohydrate and fat decomposition may
| serve as the carbon source.
|
| -
| (NO ) + 1.08 CH OH + 0.24 H CO -->
| 3 3 2 3
| -
| 0.056 C H NO + 0.47 N + 1.68 H O + 0.056 (HCO )
| 5 7 2 2 2 3
|
| Omitting bacterial synthesis:
|
| - -
| (NO ) + 0.833 CH OH + 0.167 H CO --> 0.5 N + 1.33 H O + (HCO )
| 3 3 2 3 2 2 3
|
|
| Note that in nitrification, nearly 2 mEq of bicarbonate are consumed
| as 1 mEq of ammonium is oxidized to 1 mEq of nitrate while in
| nitrification, only 1 mEq of bicarbonate is produced by reducing 1 mEq
| of nitrate. On balance, a progressive loss of alkali and an increase
| in carbon dioxide will result unless some means are taken to correct
| this.
> The pH in my aquariums is quite low; lower than can be accounted for
> by CO2 injection. I wondered if this was due to humic acids or from
> the nitrification process. A much stronger acid, sulfuric acid, could
> that also result from the decay of organic material?
I would vote for nitrification. I don't think the prcesses in the
aquarium equate to titrating with sulphuric acid. Any sulphates that
are produced are generally benign. Note that Gianascol ignores
sulphur due to its low concentration. This is true unless your
system is seriously screwed up.
> How does one obtain long term pH stability in those aquarium systems
> where water is not changed regularly?
The first suggestion is to change water regularly.
The next suggestion is to monitor KH and replace that which is used up
by nitrification. A good target is 3 dKH (~50 mg/l CaCO3 equivalent).
George in Loveland, Colorado
- - where you should always look *both* ways when crossing a one-way street
by charleyb/gr.hp.com (Charley Bay (Contract))
Date: Thu, 28 Sep 1995
Newsgroup: sci.aquaria,rec.aquaria
This is a puzzle I have been trying to de-cipher for a while. I find
I need some input.
ABSTRACT (my assertion):
Trickle filters, UGF, RUGF, and bio-wheels are stupid. We don't
need them. They are merely nitrate factories. Really, WHAT
WE NEED is nitrogen consumers or nitrogen sinks in our systems.
I'm reading my recently acquired Baensch Atlas (#1), and am pleased to
find such an overt statement:
"For both biological and aesthetic reasons, we feel live plants
and fish belong together. An aquarium with living plants means
healthy fish and though it requires more expertise than a tank
with plastic plants, it is well worth the effort." (Page 6)
I'll add to that: It also is more expensive. It requires a greater
infrastructure. However, it may not be THAT more expensive to the
serious hobbyist because I would state that you should trade your
$200 trickle filter for a $200 Metal Halide light. Net loss of
zero. Forget the trickle filter. (Your electric bill would probably
go up, though. :-)
I have for some time that live plants were good becuase they increase
the stability of the system (and they are so much more aesthetically
pleasing to the novice and expert alike, IMHO). Maybe I'm lazy, but
I really like sustainable systems that require minimum intervention.
Even from the aesthetic side, I really like having only 20 fish
(1-2" long) in a 180 gallon heavily planted tank. It's really
not a lot of work, but a whole lot of fun to view. I may go add a
school of 20 neons, but we're still talking 50 inches of fish for
150-180 gallons of water. Combined with the plants, there's plenty to
look at.
My point: Aren't biological filters (UGF, RUGF, trickle filters, bio-
wheels) REALLY just "nitrate factories"? Can we not examine the wisdom
(or lack thereof) for this?
As I see it, there are TWO reasons for water changes in (cycled) freshwater
or marine/reef systems:
(1) High nitrates in the system must be diluted.
(2) Trace elements/nutrients must be replenished.
Of course, LOW bio-loads will decrease (but not eliminate) the need for
water changes, while HIGH bio-loads will increase the need for water
changes UNLESS THESE TWO FACTORS ARE OTHERWISE ADDRESSED. By directly
addressing (1) and (2), we will conceivably not need water changes. As
somebody just posted yesterday, a typical 55 gallon marine aquarium should
have 1/1000 of an ounce of life if we want to approximate biomass levels in
the oceans. This is a pretty serious buffer against the need for water
changes, but we do recognize the ocean gets many nitrogen sinks
(addressing item (1)) and many nutrient inputs (runoff and cycling)
(addressing item (2)).
It looks to me that (1) is most significant if the high-nitrates that
accumulate in the aquarium over time cannot be utilized in biomass
production OR otherwise removed with a nitrogen sink. For most of us
with freshwater systems, the nitrogen sink is the front yard during our
water changes. However, plants are excellent nitrogen sinks (and nitrogen
uptake is so good by plants that nitrogen availability is the limiting
factor for vegetative growth in the VAST majority of terrestrial systems).
I hear many aquarists with heavily planted tanks report nitrate levels
at zero becuase the plants utilize it all for biomass production (although
light, CO2, and other nutrients must be available). Adding a biological
filter only provides opportunity for nitrosommonas and nitrobacter to
fix the ammonia to nitrite to nitrate, simply to remove it from the (more)
toxic lower states to the minimally toxic higher state of nitrate.
However, we still end up with something that we want (evenutally) removed
from the system. So why bother? Why not just go for the source, and
remove the nitrogen immediately and directly in its lower state? plants
can more readily take up ammonia and nitrite, so why bother with the
bacteria at all? If you have plants to buffer the change, the bacteria
actually SLOWS this process down, even to the point of allowing nitrogenous
wastes to accumulate in the system.
The argument "Well, plants may not be able to buffer that change fast
enough" is baloney sausage (BS). We trust bacteria to do it, so why not
plants? Bacteria is capable of hitting a geometric growth curve in a
short period of time, yes; but these populations are largely steady-state
in a cycled aquarium, so their geometric growth curve is not an advantage
to a cycled system. Likewise, plants can easily be the established
infrastructure in the system WAITING for the ammonia to absorb, WAITING
for the opportunity to grow. Same thing. Even if the bacteria is MUCH
more efficent, (which they probably are), that is more than compensated
for by the fact that you have THOUSANDS (millions?) of times more plant
mass than you have bacterial mass in a typical planted tank. Similarly,
the bacteria IS NOT efficient at REMOVING the nitrogen (fixing it into
an inaccessible form: biomass or N2 gas). It doesn't do that at all!
(Unless your substrate went anaerobic and all your fish and plants died.)
It merely converts it to another state, which still must be removed.
Now, PLANTS ACTUALLY REMOVE IT by putting it in an inaccessible bio-mass
state. Also, your friends thank you when you give your nitrogen waste
away in the form of plant cuttings.
In marine systems, I see that this may still be a problem. Since
we don't really have many "true plants" to pick from, we can roll back
to macro-algae scrubbers to remove nitrogen waste. I know that this
takes a lot of space, and may not be feasible for many aquarists (but
should save some money on Instant Ocean; That's another issue,
though. :-) A jaubert-plenum type system with anaerobic de-nitrifying
bacteria is also a very interesting prospect, as is the same de-nitrifying
potential inside live rock. Like the Berlin reef system suggests, live
rock may be the equivalent "filter" for the ocean that live plants are
for freshwater.
For item (2), we can minimize the issue by adding nutrient supplements.
For freshwater systems, we just have to pay attention to what trace
elements the tapwater provides that we are not otherwise directly
providing with our plant fertilizers. This is possible. It may not
even be that hard, since we have a wealth of companies trying to sell
mixes of elements that are supposed to do everything for plants. It
can be quite expensive, so I'm going to put on my amateur chemist hat and
mix my own recipes of nutrient additives when my current (purchased)
stock runs out (and it's cheap, too! -- I'm hearing anywhere from 1/10
to three pennies a day for everything). You might be able to save a
bundle by not buying that $200 trickle-filter (that's almost 55 YEARS
of plant nutrient additives at a penny a day!)
Again, marine systems are (possibly) a bigger issue. I've got my eye
on reefs, where I recognize that calcium and many other nutrients are
removed from the water by invertebrates while the organic matter goes
up over time. Since the actual salinity should not change (assuming
no evaporation or "topping off" to compensate), how about a simple
product that provides the consumed elements, not the non-consumed
elements? Seems like some "Instant Ocean Supplement" for those times
between water changes is a good idea, and I have seen some products
that specifically offer consumable compounds for the reef critters
(and reefkeepers are always adding kalkwasser). Of course, much (most)
of the organic matter can simply be removed with a protein skimmer.
I'm not advocating everybody should do low bioloads. However, I would
like to suggest (and duck for the reaction) the thought that we should
be able to set up FAR MORE SUSTAINABLE systems WITHOUT emphasizing the
bacterial conversion to nitrate. (That will happen to a small degree
even if we do nothing; we just don't need to emphasize it as our primary
tool). Especially for freshwater systems, aren't these trickle filters
just nitrate factories? Why bother with them, when the same thing can
be done for "free" with nitrogenous consumers or other nitrogen sinks
(i.e., plants)?
STATED CLEARLY: We *should* have nitrogenous consumers/sinks in our
systems INHERENTLY, just like they exist in nature. For freshwater, this
is simple and proven with plants; for marine systems, it may be a little
more thought, but algal scrubbers, live rock, or jaubert plenum type
approaches seem to have merit.
Water changes simply allow us to minimize our screw-ups. It's a fudge
factor. That's all it is. However, if you want to minimize the number of
changes you need (and give your flora and fauna a MUCH better environment
for existence), we should simply ensure the appropriate SINKS are available
INHERENTLY for compounds that increase over time, and the appropriate
ADDITIVES are available for consumed compounds over time. The
water/salinity is a medium, and is NOT A FACTOR. Similarly, all
our bio-filters DO NOT PROVIDE EITHER A SINK OR A ADDITIVE to the system,
and is thus IRRELEVANT.
Clearly, we may be talking about a paradigm shift in the aquarium hobby.
Right now, I bet you get a lot of "You are running a reef WITHOUT a protein
skimmer? Are you NUTS!?" Maybe in the future we'll hear, "You have a
fish tank WITH NO PLANTS (nitrogen sinks)! Are you NUTS!?"
Is this crazy, or what?
This is why I like the bottoms-up systems approach: When you get planted
tank right, your fish are in HEAVEN. When you get a reef tank right,
your fish are in HEAVEN. Give your trickle filter away, and bite the
bullet up front and go buy the Metal Halide lights. :-)
--
--charley #include <stdisclaimer.h>
charleyb-at-gr.hp.com -or- charley-at-agrostis.nrel.colostate.edu
by rclark/alcor.concordia.ca (Richard Clark)
Date: 3 Apr 92
Newsgroup: rec.aquaria
[stuff about funny nitrate readings deleted]
You can contact Kordon product support by sending email to
72230.367-at-compuserve.com
They _may_ be able to explain your readings. I think that it's at
least a logical place to start looking for answers. Personally, I had
trouble with their nitrate kit too (reagent wouldn't dissolve) and they
told me it shouldn't affect my readings, but I could buy a standard
solution to be sure. After paying what I consider to be a premium
price for their kit, I didn't find that too reassuring.
rick
--
rick clark (rclark-at-alcor.concordia.ca)
(CIS 70272,3270)
by SRRapp/ccmail.monsanto.com (Stephen Rapp)
Date: Mon, 30 Aug 1993
Newsgroup: rec.aquaria
In article <133.59.uupcb-at-eabbs.uucp>, steve.shvetsoff-at-eabbs.uucp (Steve
Shvetsoff) wrote:
>
>
> NU>Now the kit (Tetra, measures NO-3 [ '-' superscript '3' subscript])
> NU>constantly reads 25 mg/l NO3.
>
> SR>If your Tetra kit reads 25 mg/l your actual nitrate ion
> SR>concentration is 4.4 times this (-at-100 mg/L), way to high for a
> SR>reef! Although most reef and
>
> Wait a minute, Tetra kits measure the nitrate ion level (NO-3).
> Which means to get the nitrate-nitrogen (NO3-N) level you should
> divide the level by 4.4, i.e. 25ppm<NO-3> by 4.4 = 5.6ppm<NO3-N>.
> Which is perfect. And you (Nick) should be having no problems keeping
> even the toughest inverts.
Steve,
Are you sure that the Tetra kits measure nitrate ion? For a while I
thought this was the case but when I used other kits that measure total
nitrate (LaMotte) I kept coming up with readings that, when compared to the
Tetra test, made sense only if the Tetra kit measured total
nitrate-nitrogen. After seeing your posting I called Tetra's 800 number
and the tech. specialist told me that she thought their kit measured total
nitrate-nitrogen despite the fact that the labeling on the box would
indicate nitrate ion. I dont have the directions to the Tetra kit in front
of me but I dont recall that they discuss any units (ion or total) in the
anaylsis of their test results. The Tetra tech. specialist could not
definitively find any written source in her product info. to confirm her
thoughts that the kit mesured total nitrogen nitrate however she said she
would fax their main office in Germany to find out. She will call me with
the information. Any info. you have on this matter would be appreciated.
In fact, does anyone on the net know if any of the standard kits measure
nitrate ion? I know the Hach kit does.
Thanks Steve
>
> ***** Reef Study Group, San Francisco CA *******\\Steve//
by Watford28/aol.com
Date: Wed, 19 May 1999
On APD #1039 Scott wrote:
"There is really no need to make such comments. Perhaps this is what the
person
is known as, or wishes to be known as, It is petty to suggest that he is not
to be taken seriously because he has a nickname."
It is only common courtesy to give someone your name (at least your first
anyway) when talking to them even if it is only in APD.
Next you said:
"Uncertain maybe, but we do know that Nitrobacter and Nitrosomonas are most
likely
the two genuses (hmmmm, is that the right word?)"
and...
"It is also speculation to say that these products do not work as claimed. I
do not use them but know several people who have had success with them. I know
of no actual studies to prove that they are ineffective or effective."
I am not sure of the word you mean but I hope the following information helps
clear up any questions.
Authors: Hovanec TA. Taylor LT. Blakis A. Delong EF .
Source: Applied & Environmental Microbiology. 64(1):258-264
1998 Jan. (Updated Jan. 1999)
Abstract:
Oxidation of nitrite to nitrate in aquaria is typically attributed
to bacteria belonging to the genus Nitrobacter which are members of the alpha
subdivision of the class Proteobacteria. In order to identify bacteria
responsible for nitrite oxidation in aquaria, clone libraries of rRNA genes
were developed from biofilms of several freshwater aquaria, Analysis of the
rDNA libraries, along with results from denaturing gradient gel
electrophoresis (DGGE) on frequently sampled biofilms, indicated the presence
of putative nitrite-oxidizing bacteria closely related to other members of
the genus Nitrospira. Nucleic acid hybridization experiments with rRNA from
biofilms of freshwater aquaria demonstrated that Nitrospira-like rRNA
comprised nearly 5% of the rRNA extracted from the biofilms during the
establishment of nitrification. Nitrite-oxidizing bacteria belonging to the
alpha subdivision of the class Proteobacteria (e.g., Nitrobacter spp.) were
not detected in these samples. Aquaria which received a commercial
preparation containing Nitrobacter species did not show evidence of
Nitrobacter growth and development but did develop substantial populations of
Nitrospira-like species. Time series analysis of rDNA phylotypes on aquaria
biofilms by DGGE, combined with nitrite and nitrate analysis, showed a
correspondence between the appearance of Nitrospira-like bacterial ribosomal
DNA and the initiation of nitrite oxidation. In total, the data suggest that
Nitrobacter winogradskyi and close relatives were not the dominant
nitrite-oxidizing bacteria in freshwater aquaria. Instead, nitrite oxidation
in freshwater aquaria appeared to be mediated by bacteria closely related to
Nitrospira moscoviensis and Nitrospira and marina. [References: 18]
There are longer versions available if anyone wants a copy off-line, just
e-mail me.
James Watford
Columbia, SC
by "Roger S. Miller" <rgrmill/rt66.com>
Date: Wed, 19 Jan 2000
On Wed, 19 Jan 2000, Kevin Buckley wrote:
> What I would like to understand is whether, if I were to increase my light &
> add CO2, I could ever reasonably get to the point where the plants eat all
> of the ammonia produced by the fish?
It's possible.
> Has anyone ever done a rough quantitative analysis of this? i.e. the
> relationship between "fish-food-in (grams/month), plant-material-removed
> (grams/month) & rate-of-Nitrate-change (ppm/month) given a particular water
> volume & static fish mass increase (i.e. Nitrogen-into-fish =
> Nitrogen-out-of-fish)?
I've done it, but nitrogen isn't independent from other nutrients in the
tank so I don't think it can be done in a meaningful way without also
addressing at least carbon and the other macronutrients at the same time.
It gets complicated and it's real usefulness is questionable.
Briefly:
change in nitrogen content of the tank = nitrogen in - nitrogen out
the nitrogen content in the tank includes the nitrogen in the water, in
fish, plants, mulm, snails and so on. It's very difficult to quantify.
It's simple and at least semi-realistic to assume that there's no change
in the total nitrogen content of the tank. This probably describes a
mature, carefully maintained tank.
That leaves (after rearranging):
nitrogen in = nitrogen out
To simplify things assume that you don't fertilize with nitrogen,
and that there's no nitrogen in the water you use for water changes. Fish
feeding would be the only "nitrogen in".
nitrogen out is more complicated; nitrogen is removed with plants and
trimmings, with filter cleaning, with water changes and with
denitrification. If the tank isn't filtered and you neglect
denitrification then things are simpler. The nitrogen removed by plants
is the plant dry mass removed times the nitrogen content of the plants.
The nitrogen removed in water changes is the nitrogen content in water
times the volume of water that is changed.
summarizing:
feeding rate*nitrogen content of food ~=
plant removal rate*nitrogen content of plants +
concentration in water*water change rate.
> My fish food is 48% protein, & 100g lasts me about 4 months - does anyone
> know how much Nitrogen that represents? What is the Nitrogen content of
> 'wet Vallis'?
Proteins (collectively) are about 16% nitrogen. To get the nitrogen
content of the fish food, just multiply the protein content by 0.16 (or
divide it by 6.25 -- same thing). 48% protein translates to 7.7% N.
100g of fish food then would contain 7.7 grams of N. Over 4 months,
that's 64 milligrams/day.
If plants are really nitrogen starved, then their nitrogen content might
be as low at 16 mg/gram (this is from the "Critical Concentration" given
by Diana Walstad). At that concentration, your 64 milligrams/day of
nitrogen in fish food would produce 4 grams of dry plant mass per day.
Aquatic plants are mostly water. I don't know what vals are, but I seem
to remember that the normal number is something like 95-97% water by
weight. If the plants are 95% water, then 4 grams of dry plant mass per
day would translate to 80 grams of actual plant mass per day.
Your plants aren't nitrogen starved, so their nitrogen content should be
much higher than the critically low value. The approximate concentration
that Karen Randall gave in one of her AFM articles was 1% to 3%; Diana
Walstad reported that a mixed population of plants from her tanks (low
tech and not nitrogen limited) was analysed to contain 3.9% nitrogen. If
your plants ran about 3% nitrogen (30 mg/gram) then the nitrogen in the
fish food would be contained in 2.13 g/day of dry plant mass, or about
42.7 g/day of wet plant mass - close to 300 grams/week.
If you can grow 300 grams/week (or so) of plants, then the plants can
contain all of the nitrogen you add with the fish food. 300 grams/week is
about 11 ounces per week
Assume your feeding rate of 25 grams/month and feed nitrogen content of
7.7%. Say you're removing 60 grams (60,000 milligrams) of plant dry mass
per month, that the plants contain 3% nitrogen, and that you chang 38
liters of water every two weeks, or 76 liters/month. The approximate
nitrogen balance based on the formula back at the beginning of the letter
is:
25 grams food/month*0.077 grams N/gram food =
60 grams dry plant/month*0.03 grams N/ grams dry plant +
C (grams N/liter) * 76 liters per month.
This lets you (through the magic of algebra) estimate the expected
concentration of nitrogen in your water. For these numbers it comes out
to 0.0016 grams N/liter, of 1.6 mg/liter N. That would be about 7 mg/l of
nitrate. In reality it probably would be lower than 7 mg/l.
> When plants uptake Nitrogen do they preferentially take Ammonia rather than
> Nitrate or do they take both simultaneously if both are present?
Most aquatic plants seem to take ammonia by preference but will take
nitrate if they need it. In a mixed community of plants you're likely to
have some that use ammonia and some that use nitrate.
> Also, do, fish faeces biodegrade into something other than Ammonia (related
> to the previous point)?
Fish feces degrades to a lot of things other than ammonia. Most of the
nitrogen content of the feces should be in amino compounds, including
undigested proteins. Some of these compounds will be broken down by
bacteria to release ammonia but some of it will be pretty refractory; it
won't break down quickly - in fact it may never break down - and it will
end up as a permanent, benign nitrogen content in the mulm.
Fish release ammonia through their gills and urine. Ammonia derived from
decomposing feces isn't the only source of ammonia in an aquarium.
Roger Miller
The Krib
Chemistry
The Krib