CO2 in Nature.

[Whiskey]

Hello all!

Tom has linked this Tropica Aquarium Plants article many times, to many various people:
http://www.tropica.com/advising/technical-articles/biology-of-aquatic-plants/co2-and-light.aspx

It's a great article, but I have a question about one part of it.

One of the paragraphs starts of like so:

In nature, the concentration of CO2 is often larger in water than in air

Is this true? Is the C02 concentration in natural lakes and streams really much higher than air? If so, how high is it? Is having say 30ppm of CO2 an environment you would readily see in nature?

I know that in my aquarium if I don't inject CO2 the plants use up what's available to them very quickly,.. I'm sure that nature would be the same way if nothing were adding it back, so where is all this CO2 coming from?

Thanks!
James

 

[Biollante]

Aquariums Are Not "Natural"

Hi James,

I recall reading about lakes in Florida with CO2 in the range of 300-800ppm.

I would think these waters so acidic that most critters and probably, plants would be hard pressed to survive.

The answer is I am sure there are places that maintain 30ppm CO2, I just cannot tell you where.

Almost ant place the water comes through limestone and hasn't been degassed by running through rapid or falls would be good places to start looking.

Many river and lake beds produce CO2 in introduce it to the water column much as deep sand beds as substrates in aquariums.

I have been repeatedly told that over 30-ppm the plants do not really benefit. My always unscientific observations suggest otherwise.

Anyway I will let the Gurus handle the this.

Biollante

 

[chrisfraser05]

as biollante says alot of the CO2 in natural enviroments comes from the break down of biomatter in the river/lake beds.

It is this reason that real soil is best to use in low tech planted aquariums as this releases CO2 into the water inplace of pressurised CO2.



Oh oh oh... Just realised this is my first post on here lol. Sometimes you forget which forums you've posted on and which you just hang about!

 

[Whiskey]

Welcome to the board Chris!

Your right,.. aquariums are not "Natural", however I always had assumed that by injecting CO2 we were creating a very artificial environment for our plants to grow in. The idea that CO2 is so abundant in natural systems is new to me,.. and if that's true it totally changes the whole way I view CO2 injection. I've always wondered how the plants in lakes did it,.. if we needed the big tank of CO2 to keep them happy,.. well! If C02 in the lake/stream/river the plants and fish come from is abundant, then I'll I'm doing is creating a more natural environment for my creatures. I like the idea of that much better than the thought that I'm somehow putting the whole thing on "Life support".

Know what I mean?
Whiskey

 

[Biollante]

Know What ya Mean

Hi Chris, James,

Welcome Chris posting is okay!

I prefer to think of our aquariums as systems, I think many problems people face are due to thinking of our little container gardens as being “nature in a bottle.” :gw

Biollante

 

[Tom Barr]

Hello all!

Tom has linked this Tropica Aquarium Plants article many times, to many various people:
http://www.tropica.com/advising/technical-articles/biology-of-aquatic-plants/co2-and-light.aspx

It's a great article, but I have a question about one part of it.

One of the paragraphs starts of like so:


Is this true? Is the C02 concentration in natural lakes and streams really much higher than air? If so, how high is it? Is having say 30ppm of CO2 an environment you would readily see in nature?

I know that in my aquarium if I don't inject CO2 the plants use up what's available to them very quickly,.. I'm sure that nature would be the same way if nothing were adding it back, so where is all this CO2 coming from?

Thanks!
James

Yes, it is true. Depends on when you take the reading and how.


Regards,
Tom barr

 

[Tom Barr]

See several threads I've posted here about CO2 in natural systems, one VERY recently.
These all have some very common themes.

Natural sediments are good for lakes and other systems as a source of CO2..........however, for out tanks, they contribute a VERY limiting rate step, it's called aerobic respiration.

Breath.........ahhh........see? You are doing it right now!!!
Since many assume this is a big deal, try blowing all that "hot air" into the tank.
See any difference? Change in Co2? How can add much CO2 without breaking down reduced carbon using O2??? The O2 has to come from somewhere right??? This works out well in a large lake with few plants, but not in a smaller tank. Some is used from this source, but much less than many seem to assume.

So to get a residual for 6-8 hours per day at say 4ppm of CO2, not much.......we'd need to consume 4ppm of O2. So now you go from 7ppm of O2, down to 3 or less..and you have fish and less flow???
This assumes that 7ppm O2 can be added back as fast it is used up to maintain 3ppm of O2.

Ideally you'd have fast flowing high rates or aeration if this where really the case.
But there's less evidence that helps.

Regards,
Tom Barr

 

[Whiskey]

Oops,... I posted asking for elaboration while you were posting your post.
I'm confused about what your saying - but I'll come back to ask questions once I look up the other natural CO2 threads you mentioned,.. I might better understand this post after I read those

Thanks,
Whiskey

 

[scottward]

Interesting stuff, a good question Whisky.

In some places plants can also supplement their CO2 requirements via aerial growth (i.e. plant sticking up out of the water)...correct?

 

[Whiskey]

See several threads I've posted here about CO2 in natural systems, one VERY recently.
These all have some very common themes.

Natural sediments are good for lakes and other systems as a source of CO2..........however, for out tanks, they contribute a VERY limiting rate step, it's called aerobic respiration.

Breath.........ahhh........see? You are doing it right now!!!
Since many assume this is a big deal, try blowing all that "hot air" into the tank.
See any difference? Change in Co2? How can add much CO2 without breaking down reduced carbon using O2??? The O2 has to come from somewhere right??? This works out well in a large lake with few plants, but not in a smaller tank. Some is used from this source, but much less than many seem to assume.

So to get a residual for 6-8 hours per day at say 4ppm of CO2, not much.......we'd need to consume 4ppm of O2. So now you go from 7ppm of O2, down to 3 or less..and you have fish and less flow???
This assumes that 7ppm O2 can be added back as fast it is used up to maintain 3ppm of O2.

Ideally you'd have fast flowing high rates or aeration if this where really the case.
But there's less evidence that helps.

Regards,
Tom Barr

Hello Tom,

Could you do me a favor and tell me what the title of the threads your refrencing here are? I tried searching, but I'm not exactally sure what I'm looking for, and nothing jumped out at me in the search results. I want to better understand where your coming from, without having to waste everyone's time asking the same questions that have already been recently answered

Thanks for the help!
James

 

[Whiskey]

Interesting stuff, a good question Whisky.

In some places plants can also supplement their CO2 requirements via aerial growth (i.e. plant sticking up out of the water)...correct?

Yeah! Lilly pads, or duckweed jump immeditally to mind - these are perfect additions to non-co2 tanks, and do wonders on making sure algae is kept at bay.

Whiskey

 

[nipat]

Hello Tom,

Could you do me a favor and tell me what the title of the threads your refrencing here are? I tried searching, but I'm not exactally sure what I'm looking for, and nothing jumped out at me in the search results. I want to better understand where your coming from, without having to waste everyone's time asking the same questions that have already been recently answered

Thanks for the help!
James

Not Tom

but I think this is a good
answer from him about this topic.
http://fins.actwin.com/aquatic-plants/month.200302/msg00327.html

The one he referred to is probably a trip that he got lost.
http://www.barrreport.com/showthrea...-in-CA-Hat-Creek-source-aquatic-plant-nirvana

 

[fgiannasi]

I don´t post here much....
But I wish to share pictures of an amazing place here in Brazil, named Bonito (translation: Beautyfull - yep, it´s the name of the city) which I found at http://www.aquamazon.com.br There we´re allowed to dive amongst astonishing places, almost feeling inside an aquarium.

http://www.aquamazon.com.br/?area=expedicoes_baia_bonita
http://www.aquamazon.com.br/?area=expedicoes_rio_da_prata
http://www.aquamazon.com.br/?area=expedicoes_rio_sucuri

There we have:
KH- 7
GH- 11
pH- 7.2
CO2- 13 ppm
PO4-

 

[dutchy]

Nice pics!!

I wonder what the water composition is here, including CO2...

regards,
dutchy

 

[Whiskey]

That's awesome!!! Thanks for bringing us those pics

Do you know where all the Co2 comes from?

Thanks!
James

 

[Biollante]

Limestone

Do you know where all the Co2 comes from?

Hi James,

Limestone is the source of the CO2.

According to the web site http://www.aquamazon.com.br/?area=expedicoes_baia_bonita "The limestone of the region of Serra da Bodoquena originates Ocean Corumbá between 550 and 570 million years."

Basically it is cool water 72 F (22 C) welling up through limestone before the river has run through rapids and waterfalls to degas the water.

Biollante

 

[fgiannasi]

This place is located above some calcarium formation, thats why the high GH and also the very clear (transparent) water.
These conditions are kept only a few kilometers from the fountains that originates the river. As the depth increases and the CO2 degasses we see a decrese in plant diversity. The CO2 clearly comes from the undergound, as it´s concentration decreases rapidly as the river goes down, as seen:

Fountain:
KH- 11
GH- 13
pH- 7.4
CO2- 14 ppm
PO4-

 

[fgiannasi]

Biollante was quick