CO2 and fish growth

Biollante

Lifetime Charter Member
Lifetime Member
Jun 21, 2009
3,210
3
36
Surprise, AZ
I Have Plump Fish

dutchy;39261 said:
Hi,

I read somewhere that excess of 30 ppm of CO2 inhibits fish growth. Is this true?

Regards,
HJ

Hi,

I have generally plump fish!:rolleyes:

I know there have been reports of fish in the ocean, growing oversized ear bones; the truth is we don’t know what the long term effects might be taking place.

I read somewhere back in ancient times when the world was young that 5ppm of CO2 was hazardous to fish and that certainly 15ppm would kill them outright. Then it was 20ppm of CO2 would be the ruination of the hobby. One of the best pieces I have read on the subject is at CO2 Poisoning it is worth, I think, reading the whole thing.

Nowadays people routinely keep a rate of 30 ppm CO2 as a matter of routine. I routinely keep 38-40 ppm CO2. I am happy, my plants are happy and my fish seem really happy. In fact the oddity of it is my Angelfish breed more readily now then back in the day when I was breeding them seriously. I have neon tetras breeding like crazy, tried intentionally for years, with little success. I have a very low mortality rate among my critters, well excluding the tasty critters…:eek:

Even my livebearers, you know the hard water fish, are breeding like crazy. I can’t figure it, it is like everyone wants to sit around scaring themselves.

Now, I have pushed CO2 levels for short periods of time, it seems one can get beyond 100 ppm CO2 before immediate ‘noticeable ‘stress and I did experience a higher mortality rate in the next month or so that I attributed to stress.

I would also be careful in paying too much attention to the ppm number. Since many factors, from partial pressure, to Brownian movement, Solvation, and Péclet number, on and on.

I keep my tanks uncovered, the partial pressure thing, combined with that Brownian movement stuff and the like. Not to mention it removes doubt about refractive indices’ and such like on calculating the effectiveness of our lighting systems, but that is another controversy, for another day (not to mention thread).

I believe the principle threat to our livestock remains ignorance and apathy. Ammonia and general poor maintenance and care stunt and kill and will continue to stunt and kill far more of our critters than CO2.

Having said that, people, we have these marvelous pressurized CO2 systems, they have needle valves for a reason, your pH controllers are no more accurate than the ph, KH tables. Be gentle, observe, then react.

My two cents US.

Biollante
 

Philosophos

Lifetime Charter Member
Lifetime Member
Mar 12, 2009
1,346
0
36
While I don't have any solid data, my experience with fry raises some CO2 concerns. I have had a female apisto continue to behave as if she's guarding eggs or small fry in her cave days after they should've emerged, which they never do. Thinking back, this behavior seemed to correlate with excessive CO2 levels. This behavior has not been exhibited when she has eaten her own young.

So while this may not cover stunting, the danger to younger fish and their health is something I'd certainly think to be relevant. The question left to me is whether it's occurring because the fry can't come to the surface, the eggs are being damaged or oxygen deprived, or whether there's abnormal sensitivity.

-Philosophos
 

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
18,699
786
113
dutchy;39261 said:
Hi,

I read somewhere that excess of 30 ppm of CO2 inhibits fish growth. Is this true?

Regards,
HJ

Breeding Discus, breeding Angelfish, breeding Cories, Breeding shrimp(CRS's and RCS) all at 35-40ppm of CO2 measured with a CO2 oxyguard meter.
My Congo Tetras are huge.

How much inhibition?
I doubt any aquarist in practical terms could notice of show this.

Where is matters is with respiration.
CO2 and O2 exchange.

If you do not have concurrent high O2 along with high CO2, then you have higher rates of breathing. So it's not just a mere question of CO2 alone for our systems.
While this is common sense, many ignore this fact.

Breathing rates are about the best indicator of sublethal stress.
We also do not suggest or require high CO2 all the time, only say 8-10 hours of the day light cycle, so about 35-40% of the 24 hour period.

Food plays a large role in growth as well.

Are fish, in general, smaller in planted tanks that use CO2?
I think that would very very difficult to demonstrate no matter what research has been done in a lab. It would take a lot of comparative work and be very specific to the respiration issue for many warm water fish species.

Little is done with CO2 and fish.

In FL, TX in the USA, in Bonita in Brasil, in New Zealand, they have some nice examples of high CO2 rich water and lush plant growth. They have nice large fish populations.

Where moderate plant biomass exist, there is higher production of fish in lakes and rivers that without, this a well known fact shown by research.
Seems to me that some of the issues that are negative are countered by the positive benefits of plants.

So who said this or where did you read this?
It MATTERS how their methods where done and what type of system they where looking at, some systems, this might be true for 30ppm and certain types of fish and without plants etc.

The real question is does it matter to us and our systems.
I do not think anyone has demonstrated it.

Regards,
Tom Barr
 

dutchy

Plant Guru Team
Lifetime Member
Jul 6, 2009
2,280
5
36
63
The Netherlands
I looks like I should have put a disclaimer ;-) Something like: "The statement is not necessarily the opinion of the poster". With a Ph of 6,7 and dKH of 6 I'm close to 40ppm myself.
Well, I read it on the Easylife site. But it's not in English. For the multilinguists:
Easy Life subsite : alles over plantengroei in het aquarium. It's Esaylife's subsite in Dutch with info about things like light, CO2 etc. Kind of basic, but useful. Anyway, I liked the responses and know now that it's just another fairytale in aqua wonderland.

Regards,
HJ
 

Biollante

Lifetime Charter Member
Lifetime Member
Jun 21, 2009
3,210
3
36
Surprise, AZ
Mijn Nederlands is niet wat zij moeten worden.

My dutch isn't what it should be,:eek: but I gather that it is a fairly routine use (misuse?) of information that has been around for quite sometime. The purpose seems to be to sell a product.

I think the are propagating the same information,frankly Tom Barr and his bunch (guess that would be, our bunch) have been fighting for some time.

I think it is fair to ask the questions, but to just keep repeating the mantra is silly.

That is my quick reaction opinion.

Personally I don't think we know enough, we need to continue asking, observing and researching, at the same time we need to be sure that what we observe and pass on can be replicated by anyone who chooses to give an honest effort.

Now having said that, I am going to spend some time studying that website before I actually give a considered opinion. As I say my Dutch isn't what it should be.

Ik zal werken op mijn Nederlandse en antwoord u in volledige, mijn vriend.

Biollante
 

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
18,699
786
113
Hummm.........yes, seems like old news.

Applying CO2 enrichment correctly to a planted tank is a different system.
The problem is many do not add it correctly, nor is it easy to do for many, some get lucky though.

Dutchy, we know it's not you personally:)
Do not fear:)

Look what a translation engine did to the poor language!


" In character 2 we see clearly that slightly leads more to higher CO2-fixatie and therefore a larger need for available CO2. "

This is good since it addresses that there are differences in plant to plant species in CO2 demand and ability. Why do so many aquarist assume that all aquatic plants are fine at the lower ranges of CO2? So weedy species might do well and out compete the other species that require more CO2, or no competitors being present.

They discuss the pH/KH which makes an assumptuion that all the alkalinity is KH, this is not the case with many types of tap water.

" Ideal is pH of 6.6 and KH of 3 to 4. This means zwakzuur water with a reasonable carbonate hardness. "

This is a good mid range, I'd say a pH of 6.2-6.4 however as some species will do better and many people have higher intensities of light, which means more light = more CO2 demand.

People often say the word "Balance" all the time in plant forums, but few understand what that really means. More light = more CO2/nutrients, less light means less CO2 and nutrients. Some plant species will tolerant much more than others.

This is common sense when you think about it, but aquarist get lost in the details far too often.

Ideal CO2-gehalte - more lower than 5 mg CO2/ltr: too a little CO2 for sufficient assimilation - between 15 - 30 mg CO2/ltr: ideal and enough CO2 for optimum assimilation - more higher than 30 mg CO2/ltr: in general the increase of the fish slows down; very high concentrations (> 40 -- 100) lead to breathlessness at the fish because it oxygen is dissipated from water.

Less than 5ppm depends as mentioned prior above, at low light itnesity, at 20 microl, many species are quite able to grow very well.

15-30 is a pretty wide range also...........and it depends on light intensity as well, as nutrients being non limiting so that the full use of CO2 can be done for the light intensity.

Oxygen is not displaced by high CO2, rather, the gills cannot transfer CO2 out of the fish's blood due to the high CO2 in the water. O2 and CO2 are independent.
We know this clearly.

High O2 levels can allow the fish to breath easier and do better, but the fish still have limits since they must also expel CO2 across a concentrational gradient.

If CO2 external = to CO2 intenal in the blood, no exchange is going to occur unless it's actively pumping CO2 out some how, not passive diffusion like in the gills/our lungs etc. All the O2 in the world will not solve that.

Many reduce the flow and other things down to save CO2, then this creates issues by having low O2(fish breath harder) + high CO2. This is the worse case.

Respiration and CO2 toxicity are CO2 + O2 and how much transfer energy from the concentration of the external water vs the blood concentrations for CO2.

They have to get rid of the CO2.
That is the limit for ppm's of CO2.

CO2 ppms prior to "stress" can be measured in fish blood.
Overall, the advice they give is fairly good.

Much better than most web sites a decade ago;)

Regards,
Tom Barr










Pursuit we a good plant increase after, then there therefore also sufficient CO2 available must be. If we arrive after measuring the pH and the KH in the green areas of the table, then we know in any case that water contains probably sufficient CO2 for a good plant increase and that this value is be not too high for detrimental for the fish by an undesirable oxygen exorcism.
 

Biollante

Lifetime Charter Member
Lifetime Member
Jun 21, 2009
3,210
3
36
Surprise, AZ
Ik ben het eens met Tom Barr

That is almost as bad as my Dutch! :eek:

I think I may have over reacted on my first look, I agree with Tom Barr's take it is just out of date material.:eek:

It seems kind of odd to me, the "Easy Life" folks actually seem rather sophisticated. Maybe just lazy?:rolleyes:

Ik ben het eens met Tom Barr wij hebben niet de echt schuld u.

Soms krijg ik overdreven uitbundig, neemt u mij niet kwalijk als ik u beledigd.:)

Biollante
 

Biollante

Lifetime Charter Member
Lifetime Member
Jun 21, 2009
3,210
3
36
Surprise, AZ
Google Translation Tool

Wow, I feel like a bigger moron than usual. :eek:

I just “found” Google Translation at Google Translate, just go to “Tools” click on your language and drag to your tool bar. I cannot believe the quality of translation, at least it appears grammatically correct.

Wow, I could have set here for a week and not come close.:mad:

Wow, ik voel me als een idioot groter dan normaal.

Ik heb net "gevonden" Google Vertaling in Google Translate #, ga dan naar "Tools" en klik op uw taal en slepen naar je toolbar. Ik kan niet geloven dat de kwaliteit van de vertaling, althans lijkt grammaticaal correct zijn.

Wow, ik kon hebben hier voor een week en niet dichtbij.

Google translated that. It seems correct to me.

Alle inspanningen heb ik in leren Afrikaans, dan Nederlands, ik was altijd spookt door mijn "Afrikaans accent", terwijl in Nederland.

Ik ben niet zeker dat ik zou hebben gehad had ik een dergelijk instrument.

Biollante:cool:
 

dutchy

Plant Guru Team
Lifetime Member
Jul 6, 2009
2,280
5
36
63
The Netherlands
I'm really surprised about the language skills here!!:) basically the site is nice, they even address the "light break" that some people do and that it's not about the algaes that can't stand this but that it's about preserving CO2 in non CO2 tanks.
Still there are a lot of misconceptions going around. I put a link on another website to Vaughn's post of PAR readings and the WPG rule, which I defended as being the right way to do things. I was almost banned from the site!!;) People believe in a concept and it's very hard to make them change there point of view.
To me it's not strange. I've seen this happen in a lot of different areas of science.
For me, the things I believe is what I see and what I can read based on logic and reproducable research, not on assumptions. But maybe that's because I'm an engineer.

I don't see any problem in having 40ppm of CO2. Almost all my fish breed in my tank (tetra's, angelfish) and to me it's logic that unhappy fish don't breed. Thanks to the info on this site and Tom's help things are even going better now.

Regards,
HJ
 

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
18,699
786
113
dutchy;39327 said:
I'm really surprised about the language skills here!!:) basically the site is nice, they even address the "light break" that some people do and that it's not about the algaes that can't stand this but that it's about preserving CO2 in non CO2 tanks.
Still there are a lot of misconceptions going around. I put a link on another website to Vaughn's post of PAR readings and the WPG rule, which I defended as being the right way to do things. I was almost banned from the site!!;) People believe in a concept and it's very hard to make them change there point of view.

Well, there is a difference between a constructive non personal debate/argument vs a person that has no substance to add and only wants to disrupt.

The "right way to do things" needs to be qualified and reasoned for a particular goal. Not everyone's right way will apply as there are many different goals.
For a simple non CO2 planted tank, I do not think there is any demand for a PAR meter, be nice to have the data, but hardly critical.

As you spend more $ and get more into higher lighting, and other facets, then such equipment becomes more useful to aquarist. Still, I suggest group buys, sharing the meter amongst your fellow aquarist locally.

Would the people on that site like to borrow the PAR meter?
Haha! Suddenly they would line up pretty fast and see for themselves.

Once they demonstrate and prove it to themselves, then they have a different view. Until then, they will be skeptical.


I'm no different.
However, I ask skeptics to prove things to themselves as I do for my own curiosity. I want to know and willing to test and buy a meter to see.
So do not blame them too much please, have compassion, do not take it personally.

To me it's not strange. I've seen this happen in a lot of different areas of science.
For me, the things I believe is what I see and what I can read based on logic and reproducable research, not on assumptions. But maybe that's because I'm an engineer.

Well, this is part of it for you, Biologist and Reef folks often have an easier time with some of these issues in social web settings.

I don't see any problem in having 40ppm of CO2. Almost all my fish breed in my tank (tetra's, angelfish) and to me it's logic that unhappy fish don't breed. Thanks to the info on this site and Tom's help things are even going better now.

Regards,
HJ

Well, they may breed and still be stressed, I did not say that, just that the fact they do breed, which may mean that it is not too likely that they are stressed. Unless they can verify that they are indeed stressed, and breeding, which is a much harder issue to demonstrate.............I remain skeptical of such claims.

What may occur, and I think this applies better to CRS, perhaps CRS as well, is that they will still breed, but the no# of brood produced is lower than say in a non CO2 enriched aquarium.

That is a logical argument, but one that few have ever shown in aquariums.
Still, I think with RCS and CRS(shrimps), they are prolific breeding, hyper sensitive to metals, CO2/O2 respiration issues, and make for a much easier model to work with for such test.

Unlike many aquarists, I look for test that aquarist can do to answer such questions themselves. I suggest them, detail the methods out etc.

I'm not just spreading fear and myth.
I'm trying to get answers to questions.
Focus there and in time, you will learn much more.

Regards,
Tom Barr