# N - C ratio The future ?



## @tom (Jan 4, 2005)

Hi There

I was wondering if anyone in the us is testing or using different type of frozen food
to control the total ratio of nitrogen and carbon in there tank.
In holland a small group of people is doing this and are getting some good result.
Changing the ratio wil lead to very clean tanks with beautifull plant growth.
The equipment can be reduced.
Less co2 and no ppmd has to be used.

I will supply more info upon demand ..

Greetings ..


----------



## ShaneSmith (Feb 15, 2004)

I've never heard of this before, can you elaborate?


----------



## plantbrain (Jan 23, 2004)

N is high in fish food relative to P. So P will always be in a lower ratio to N as far as plant needs.

Carbon is quite another issue entirely. Far more carbon as CO2 will enter through the air above than the food source. That carbon source is stored and eventually will be used by algae, plants, or gassed off, just like C02 enrichment. We have done Carbon tracer studies at UC Davis here. The Carbon atoms can be traced through a systemand relative % of each source of carbon, such as the % ratio from fish food and the % from the air and other sources can be determined.

Also, the tap water and the source water for water changes plays a huge role. Simply feeding more vs changing the food type may give you the same results, I suspect prior, you were N limited, rather than some C/N ratio issues.

Regards, 
Tom Barr


----------



## @tom (Jan 4, 2005)

Well I agree , with you Tom that P is often a limiting factor.
But using our feeding method will free up all plantnutrients accept K.

The proces consist of 2 steps that, when combinend result in lower needs of plantnutrients.

First, you slowly change from your current fishfood source to using frozen food species
with a low C - N ratio such as Mysis and Bosmina.
This will result in faster and total microbial decomposition.
So your bottem becomes cleaner and higher amounts of elements can be used by your plants.

Some high tech research is in this http://perth.uwlax.edu/biology/aquatics/Strauss and Lamberti 2002.pdf

The second step is in reducing our filtermaterial.
Biofilms in filters take up huge amouts of nitrates and TE's for there metabolism.
So we got ride of all filtermaterial and simply use them for only heating, co2 addition and water flow.
However some plants simply will not grow if there are no nitrates.
So you'll have to add a fluid-sand-filter for this purpuse.

The only element that can't be found in this fishfood is Potassium so
that's all you need to add extra.

All basic rules for a planted aquarium still have to followed.
So you will still have to add co2, plenty of light, regular
water changes and have a low KH.

Most research into this stuff has been done by leading dutch biochemist Adriaan Briene.
Before this he also studied the Redfield ratio ( N - P ratio )
His pages are in dutch but can be found here.
http://members.lycos.nl/brieneoord/aqua/zooplankton.html
and here
http://www.xs4all.nl/~buddendo/aquarium/redfield_eng.htm

Give it a try, and you'll see some amazing results.

Greetings


----------



## plantbrain (Jan 23, 2004)

@tom said:


> Well I agree , with you Tom that P is often a limiting factor.
> But using our feeding method will free up all plantnutrients accept K.


Well, you have to add enough of the nutrients in a balanced ratio for a given growth rate otherwise this will not be true.Carbon is *not part *of this equation in terms of __plant growth__ which is what I stated previously.

Carbon as an electron donor can be limiting in some soils with little organic content, eg the bacteria are carbon limited, this is not the same as "CO2" limited. Plants are never carbon limited in this senmse, they are autotrophes, wereas the bacteria in the referenced paper are heterotrophes.



@tom said:


> The proces consist of 2 steps that, when combinend result in lower needs of plantnutrients.


I am not clear what you are are saying here. You get the same plant growth with less nutrients? The nutrients still need to come from somewhere ansd the rates of plant growth are directly related, there is no way around a simple 2 box model, what goes in MUST come out.
Food in, plant growth out.



@tom said:


> First, you slowly change from your current fishfood source to using frozen food species
> with a low C - N ratio such as Mysis and Bosmina.
> This will result in faster and total microbial decomposition.
> So your bottem becomes cleaner and higher amounts of elements can be used by your plants.


Well this is bacterial decomposition/remineralization. A good substrate, filter, water changes etc will facilitate that. Carbon can be limiting to the bacteria in a *NEW* tank, I suggest adding some peat and mulm from an established tank for this precise reason, the bacteria need some carbon to live on, new tanks are often lacking. But in an established tank, carbon is non limiting as the bacteria play a decreased role since the plants use up the nutrients. All the bacteria are doing for you then is taking bound organic carbon and oxidizing it to CO2.

Which is my point in my last post.
The N is going to be used up by the plants once the fish excrete the waste as NH4+.
Plants will not use the Carbon, they will use some of the CO2 once the bacteria cycle it.
See if you can measure any NH4 in a well run plant tank.



@tom said:


> Some high tech research is in this http://perth.uwlax.edu/biology/aquatics/Strauss and Lamberti 2002.pdf


It's research I'm very familar with, I've studied this precise topic in depth at UF in grad school with the top person in the world in biogeochemistry in wetland soils, Dr Reddy. 
Your _application_ of this research is what I'm questioning here.
The fish waste is a very labile form of DOC, plants are not DOC limited. bacteria can be. As you increase DOC and POC, this places a strain on the O2 levels, these increased cycling rates by these heterotrophic bacteric also directly correspond to an increase in O2 consumption as they oxidize the DOC into CO2.
But bacteria play minor roles in planted tanks, the main player is the plants as far as N is concerned.

Algae and plants are not Carbon, DOC limited. They might be CO2 limited.
Adding a different C ratio of food, eg, high Carbonhydrates migth help the bacteria population grow, that might help NH4 removal, but plants are much better in general at removal of NH4.

But a good bacterial colony is a good backup should you neglect your plant's needs, but so is a decent filter I do not think the role of bacteria and Carbon is significant as you contend and you have not offered any compelling evidence to suggest otherwise in the research nor observational.



@tom said:


> The second step is in reducing our filtermaterial.
> Biofilms in filters take up huge amouts of nitrates and TE's for there metabolism.


So how much TE and NO3 do aerobic bacteria in the filters are use up?
Please tell me how a filter that is aerboic with redox values at 350-500mv is able to reduce NO3 to N2 gas?The denitrifiyers neeed a range of redox values around 200-300mv This may occur in the substrate, but not in the filter in any significant way. This is easily testable by an aquarist with a good set of kits.
See how much NO3 is removed by removing the plants and letting the filter remove it.

I think you will quickly see that it doesn't do much
This is common sense, not technical science.



@tom said:


> So we got ride of all filtermaterial and simply use them for only heating, co2 addition and water flow.
> However some plants simply will not grow if there are no nitrates.
> So you'll have to add a fluid-sand-filter for this purpuse.


FSF are poor filters IME and IMO.If they stop running for 15 minutes or more, their colonies die off fast. Also, adding filtration only changes the NH4 to NO3, you first need to have NH4 to begin with, in planted tanks I have not measured any NH4, it's used up by the plants as fast as it's produced.

We have done some tracer enrichment studies with N15 and I plan on doing some here at UC Davis with radioactive N rather than mass spect type work.



@tom said:


> The only element that can't be found in this fishfood is Potassium so
> that's all you need to add extra.
> 
> All basic rules for a planted aquarium still have to followed.
> ...


Why a low KH? I do great at high KH's, research both in natural systrems and in lab studies show plants do better in higher KH's. There are relatively few exceptions(1% of the commonly kept aquatic species), but even those will grow.
Also, water changes: thius removes N and C each time, therefore the role of the bacteria is *GREATLY *reduced in decomposition's role.

Your exporting all the C and N from this system which was your original premise. This nulls your entire argument.



@tom said:


> Most research into this stuff has been done by leading dutch biochemist Adriaan Briene.
> Before this he also studied the Redfield ratio ( N - P ratio )
> His pages are in dutch but can be found here.
> http://members.lycos.nl/brieneoord/aqua/zooplankton.html
> ...


Okay, this guy, I keep hearing this Redfield ratio pop up from the Dutch sites.
There is a problem with this concept and notion and I've argued it into the ground several times with no real response back that had any merit.

Redfield ratio deals with nutrient limited open ocean phytoplankton. Aquatic plants are radically different and totally different in terms of a niche. They also possess different ratios, roughly7 10: N ratios, FW algae, about 14:1 on average if you review the relevant research on specific FW plants and algae. I've done that.

The other issue with the Buddy ratio and that whole mess: it assume you can limit the algae through ratios and such, those references are for marine phytoplankton algae, not FW systems. The other issues: aquatic plants and small algae are not even in the same niche and therefore do not compete for the same resources, even if they use the same things such as N, the scale at which they become limiting are enormously different.

It's like suggesting mice and elephants are in the same ecological niche, again common sense says otherwise.

Science is useful, how you apply it and accept it is another matter.

Bringing up the DOC issue is good, we had suggested adding glucose to the water to amplify the bacterial growth as this is gone in research for studies on carbon bacteria limitations. We discussed this years ago on the APD in more detail as it applied to planted tank, Neithe rI nor Roger Miller found an effect.

I have a hard time seeing that it would for the reasons stated here as I have not been able to show that is did anything on a more practical and controlled manner for planted tanks.

Then the food source does not matter and this allows you independent control of things like C and N and K etc in a planted tank or a wetland or a growth chamber etc.

My critque here is not personal, but the arguements present do not make much sense based on the research and the application. To the average aquarsit without a background in biogeochemistry of wetlands, they might certainly seem convincing though

But it's specificaly what I do for a career and hobby, not many are that lucky.

If you are inteersted in knowing more about DOC/POC and carbon's role, and a ton of references on this subject, I will have an article coming out on the www.BarrReport covering Carbon in great detail.

This(carbon) is the core of biogeochemistry in wetland soils and is heavily studied in the USA in Florida.

Regards, 
Tom Barr


----------



## @tom (Jan 4, 2005)

*thanks thanks thanks*

Hi

Sorry for my late reaction, testing , testing, good testing take's time.
Thank you, for your good and extended vision on this topic.

I will agree on most of the things that's you typed.

>> Food in, plant growth out. <<

This way is still growth limited by the amount of TE's that comes from the food.
Many tanks run that way, and I don't feel the need for speed.
Comparing this, with your EI / armano style of planted tank running is useless.
Simple thinking by me : light W/gal x 10 = co2 level

The point is to decompose N, C and P by using the right c:n ratio without losing it to sediment or filter uptake by
regulating the amounts of heterotrophic and nitrifying bacteria.

This info is about http://www.iwaponline.com/wst/03101/wst031010195.htm denitrifying.

The FSF is used for it's thin biofilms and creating the still needed no2.
Filters are never to be stopped..

Water changes ( 25% / 2 weeks RO water ) is done only to prevent inhibition / toxicity.
Plants will also have that effect.
Ca release from the food also increases the kh slowly. ( Low Kh )
Ca will also bind to P and Fe ..

The redfield ratio has been debated since release on many forums.
Problems lie in the P factor, it often forms ion-bindings that won't show up.
The total nutrient flows are more importend.
I'm interested in the R&D that you have been doing on algea conditions and
the NH+ levels, did you put any detailed info on the net about that ?
Just started with your site ?

I'm also one of the people that's isn't affraid of watching tanks get filled with algea.
The more we learn , the beter we can help others.
I'm still young in that way.

A lot of research into this method still has to be done, as you sad, before all factors and underlying mechanisms are clear.
Comparing a planted tank to a huge natural ecosystem is also useless.
We simply don't have the facilities and capabilities that you have.

Try using wodka as a form of C that'll do the job ..
Not all researcher found liniearity between labile and stabile doc and denitrification.

Good luck with your new job ..


----------



## plantbrain (Jan 23, 2004)

@tom said:


> Hi
> >> Food in, plant growth out. <<
> 
> This way is still growth limited by the amount of TE's that comes from the food.


Depends on the plant's growtrh rates, if limited with low light, no CO2 additions, it can supply the needed nutrient demands for months, years even.
Substrate sources can provide this since the amounts of TE are very small, while a nutrient like NO3 is very large and the substrate source might run out after a month. 
Fish waste alone cannot supply a high light tank with CO2 and dense plantings. 
You'll get algae due to NH4 not being cycled fasted enough=> leads to algae blooms.

You can test that fairly easily.



> Many tanks run that way, and I don't feel the need for speed.


I think the proper question is how fast do you wish to grow the plants?
I use 3 basic groupings: Slow, medium and fast.

Slow: non CO2, low maintenance, nio water changes, general neglect, tanks look quite good, fish health is good, the plant health is not 100%, but that's not the goal here, decent looking tanks can and are acheived, it requires patience. 
Medium: Low light still, but with rich CO2.
Dosing/water changes are done weekly, slower gerowth, easy to grow any plant, light slows the growth rates down, thus the uptake, there is a lot of wiggle room with routines and dosing here since the uptake is slowed down and the plants do not suffer right away.
Good for most folks over the long term.
High light: great for gardeners and scapers wanting to have dense growth and to prune and grow plants fast.



> Comparing this, with your EI / armano style of planted tank running is useless.


No, not really, Amano and myself use both high and low light approaches and use them effectively to reduce dosing and pruning issues. 
Many Europeans use less light than folks in NA. That allows more wiggle room with differnt dosing routines.

When you add more light, you quickly find that many of the routine that worked at lower light, now give you trouble.

Reliance on fish food declines as you add more and more light and you must add inorganic forms of N, such as KNO3, as NH4 forms will cause algal blooms.
NO3 is far more benign than NH4.
As loing as the NH4 is maintained at very low levels(in = out) things work well and for the same reason reagding algae control and plant health.

If you unbalance these, you will get algae or plant deficicency issues.
That's the balanced part

It's all about rate and what rate you desire for your given goal and routine and habits.

The Amano style and the EI both work at high abnd low light ans can still be done well at any of these lighting/methods, even non CO2.

I've done 2 non CO2 planted tanks with no fish.
It was fairly easy to maintain nutrient level at very low dosings 2x a week using inorganic nutrients. I did water changes once every 3-4 months after a pruning.



> Simple thinking by me : light W/gal x 10 = co2 level
> 
> The point is to decompose N, C and P by using the right c:n ratio without losing it to sediment or filter uptake by
> regulating the amounts of heterotrophic and nitrifying bacteria.


Removing a biological section of the filter means you simply allow more NH4 to use used rather than having it convert to NO3........the amount of N is still the same.......the bacteria population only regulate the FORM of N, not the export/import.......... the amounts of C used by the bacteria from food is rather small in the overall CO2 demand and import/export of CO2 with the air above.

In highly productive areas where there is a large amount of organic material accumulation occuring, like a nasty swamp, then a fair amount of CO2 can come from these sediments, but our tanks are not very rich by comparison.



> This info is about http://www.iwaponline.com/wst/03101/wst031010195.htm denitrifying.


You need to be specific with this, all I get is a listing or journals. Therer are many denitrying studies done on wetlands and bogs.
Do these apply to your tanks? Do we weed and add fish food to these natural systems? What are the organic matter loading rates in these systems?
The OM loading rates are much higher than our tanks.

This is easily testable.......
Remove the plants, add only NO3 as a source.......see how much is removed, the amount without the plants removed will be lower since the plants pump O2 in the substrate and reduces the denitritying bacterial regions.

Measure how much loss of NO3 you obtain over a week's time, then add the plants back and allow them a couple of week to grow in and measure this difference.

The NO3 removal is very low relative to the plant's uptake. 
That also does not include the NH4 removal plants also do.

I know wetland denification is well explained in Aquapalnta and Reef Art. I made a detailed diagram of all of the N cycling processes that occur in a submersed wetland soil.

Wetlands can become Carbon limited in some cases: Reddy, White have done a fair amount of research on this issue. See this thread for more on C:N issues and food. Many reef folks limit their food way down.

http://reefcentral.com/forums/showthread.php?s=&postid=4135659



> The FSF is used for it's thin biofilms and creating the still needed no2.
> Filters are never to be stopped..


Yes, but with routine pruning, these films are minimized, with good plant, they are also minimized as well. Algae and other eipihytes also form in these thin film spaces.



> Water changes ( 25% / 2 weeks RO water ) is done only to prevent inhibition / toxicity.


Okay, like what might be toxic or inhibit growth......eg what specific level of something is required for this to occur??
I've gone years without a water change, I have friends, that have 2-3 years without one.............N is low..........fish breed etc............
Again, it gets back to rate, the faster youm go, the more issues you will have with things running out nutrients, rather thann toxic effects from build up.
Espeically when all you rely on is food alone.

You can rely a fair amount on food with low light, but topping it off with some inorganic macros will improve the plant's health and make the tank look better. Balancing food for the plant's health is not perfect, there are trade offs..............



> Plants will also have that effect.


What effect? Allelopathic? I don't think so, this is easy to test for.............here we go again...........
Add carbon, carbon will remove any allelopathic compound, this is the standard control for aalelopathic compunds done in research.
Additionally, allelopathy has never been shown in the field in any aquatic plant on algae or another plants ever to date.............
Additonally, allelopathic compound produced by all 300 or so aquatic plants species all produce the same effect and the same intensity on algae?
What are th eodds of this ocurring?
I'll tell, you none. Well perhaps a few trillion to one



> Ca release from the food also increases the kh slowly. ( Low Kh )
> Ca will also bind to P and Fe ..
> 
> 
> ...


----------



## plantbrain (Jan 23, 2004)

> Problems lie in the P factor, it often forms ion-bindings that won't show up.
> The total nutrient flows are more importend.


I've discussed SRP and DOP and DIP at lengths on the APD and elsewhere. 
Total PO4 test will measure this fraction, it will not measure preciptated FePO4 for example.
But we have 1-2ppm of PO4 coming from an inorganic source: KH2PO4, this is inorganic SRP PO4. This is the plant biolavailable form, algae can use organic forms of PO4, the sediment will have PO4 accumulation in the form of precipitate, but this has limits before this begins leeching out in the reducing layers o the substrate and re enters the water column in bioavailable forms.

I dose PO4 regularly, many do.
You can measure it via no plants and with plants for a control as far what fraction is removed by the plants themselves.

You can also see the plant's response to addition of PO4 as a dramatic increase in plant production.

Any one can do this and see it for themselves.
I suggest you do the same. Then you'll know.



> I'm interested in the R&D that you have been doing on algea conditions and
> the NH+ levels, did you put any detailed info on the net about that ?
> Just started with your site ?


Over the years I've written volumous amounts of information about my findings starting about 10 years ago, 8 years ago on the web.
I knwo what cause algae species specific growth, I can culture these algae and then test the responses. Then repeat it and see what other folks have found.



> I'm also one of the people that's isn't affraid of watching tanks get filled with algea.
> The more we learn , the beter we can help others.
> I'm still young in that way.
> [/qoute]
> ...


----------



## @tom (Jan 4, 2005)

Thanks again Tom,

For explaining all items that come with the EI en general plant growth.

>> They will run counter to what you have learned thus far from the sounds of it. <<

No actually not ..
I have made some misstakes with overdosing the wrong stuff.
Found that not all TE sources have the right components for MY tanks.
Did a fair amount of DIY testing for co2 enrichment.
Found a dry food that containt a good amount of P.

The thing with ca and fe was my fault ..

Bye bye


----------

