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150 ppm co2?

Hi all,
We have aquatic plants and non-aquatic plants, but what is a semi-aquatic plant?
No, we definitely don't have two pigeon holes "Aquatic" & "Non-Aquatic", what we have a continuum from <"xerophytes to hydrophytes"> and there are plenty of plants in the semi-aquatic category.

Because plant producers (Tropica etc) want to grow their <"plants emersed">, they are looking for plants like <"Rotala rotundifolia">, <"Hygrophila corymbosa">, <"Echinodorus"> & <"Cryptocoryne"> spp. etc which will grow submersed, in some cases for very long time periods, before flowering when the water level falls.

Some plants <"are less successful"> long term and will either flower, or die in the attempt.

Here are photos of two Water Crowsfoot Ranunculus spp. (from last week) that are on the aquatic end of "semi-aquatic". <"Ranuculus hederaceus"> and <"R. baudotii">.

R_hederaceus.jpeg

R_baudotii.jpeg


cheers Darrel
 
Unfortunately not, I don't have access to Nature as a journal.
Hi Darrel and @22802:
In water it turns out there is a fairly linear correlation between partial CO2 (uatm) and ppm. The conversion depends on temperature and salinity. At 20C at extremely low salinity it's approximately a factor of 0.0017. So for converting the scale from pCO2(uatm) to CO2 ppm in Outgassing from Amazonian Rivers and Wetlands as a Large Tropical Source of Atmospheric CO2. E. Richey et. al. figure 3a and 3b:

pCO2(uatm) -> CO2 ppm.
2 x 10^3 = 3.4 ppm.
4 x 10^3 = 6.8 ppm.
8 x 10^3 = 13.6 ppm.
12 x 10^3 = 20 ppm.


Cheers,
Michael
 
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I think the issue for us is that most of the plants we grow aren't really obligate aquatic plants (without a cuticle or stomata etc), but they are semi-aquatic emergent plants and they really want to get at the 420 ppm of atmospheric CO2.
Hi @dw1305
I guess I used wrong word. Instead of,

"The study is about high CO2 inhibiting aquatic plant growth."

I should have said,

"The study is about high CO2 inhibiting growth of a plant we keep in aquariums."

Egeria densa - Tropica Aquarium Plants

Then it would't create such havoc. My apology.
 
Hi all,
The study is about high CO2 inhibiting growth of a plant we keep in aquariums
I've been thinking about this and I'm guessing that obligate aquatic plants from hard water (so plants which always <"get their DIC / TIC in the form of HCO3-">) are likely to be inhibited (or not be able to utilise) higher levels of CO2, because they are never going to experience them in the wild, they are adapted to using bicarbonate (HCO3-).

wqassess3bpict1-gif.gif

<"This doesn't apply to floating plants">, because they always have access to atmospheric gases, via the stomata in their upper leaf surfaces. This access to atmospheric gases (<"Diana Walstad's "aerial advantage">) is why <"floating plants can utilise more of the nutrients in the water">.

cheers Darrel
 
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It seems entirely logical that there would be some ‘aquatic’ plants that prefer lower Co2.

In our aquariums, folks are often looking for ‘optimal’ growth and form, whatever that looks like in our eyes. (The plants are probably less bothered about being perfect) Optimal growth conditions are always going to be different for different plants and therefore practical application of our husbandry methods can only be based on finding an appropriate ‘centre line’ for whatever selection we choose to keep.

My question would be, why wouldn’t there be plants that are inhibited by high Co2? Simply on the basis of ‘all things under the sun’ there are bound to be some that fit that bill and the family of obligate aquatic plants, that are never (in nature) exposed to atmosphere and have evolved therefore to live permanently in a lower Co2 environment, may logically contain those candidates.

I’d guess however that there are also obligate aquatics that would do perfectly fine with higher Co2. Figuring out which are which may be entirely dependant on popularity of, or level of desire to keep, a specific plant.

After all, much of the knowledge of how to best keep aquarium plants will come from aquarists so some of these plants may be ‘known’, others not so much.

So, again, with no scientific evidence, you can probably take out any and every aquatic plant that can be successfully grown emersed (makes sense right) so then you just gotta figure out if any of your obligate aquatics perform better with lower Co2 and then, to achieve optimal form, not grow them with plants that prefer ‘high’ Co2. (Oh and then match them to their other optimal parameters, such as nutrient/light levels etc….Easy 👍………ok maybe not!! 😏)

If of course the ‘high’ Co2’ level that inhibits such plants is, in fact, notably higher than 30ppm ish, alot of us can just go back to watching eastenders now. 😊

And anyone that wants to run Co2 at higher than 44ppm and also grow Elodea Densa at optimum, might be out of luck I guess.

As for full, 1/2 and 1/4 Co2. If full is 30ppm (and most folks would consider that to be the case) then there would need to be strong evidence that a number of plants are detrimentally effected at levels lower than 30ppm for that to ever be relevant and I’m not seeing that in this study!

Anything above 30ppm might need a new category. Full plus? super full maybe? 😊 but, as this study allows up to 44ppm (I believe!) I’m still thinking the list of plants that would actively suffer within any range that is normally implemented by aquarists would be pretty small.

Just my 2pennies worth! 😊

As for 150ppm. I’d be interested to see physically how that could be achieved 😳but in a practical sense, seems like ‘Co2 is free’ taken to a whole ‘nother level! 😂
 
Hi all,

I've been thinking about this and I'm guessing that obligate aquatic plants from hard water (so plants which always <"get their DIC / TIC in the form of HCO3-">) are likely to be inhibited (or not be able to utilise) higher levels of CO2, because they are never going to experience them in the wild, they are adapted to using bicarbonate (HCO3-).

wqassess3bpict1-gif.gif
Interesting.
If we take this idea further then submerged plants utilizing bicarbonate have as much carbon available in aquariums with medium to high KH as in the nature under direct sunlight. We can't give them more KH unless we go for unusually hard cave water levels. So this is the maximum carbon they get under full sun.

But with CO2 as a carbon source we don't have this option of maxing out CO2 due to fauna limits and the many unknown in CO2 infusion process. Or I am completely wrong?
 
I hope MrTank has not been scared away from his own thread! I'm looking forward to photos of the plants in his 150ppm CO2 tank and what the differences are compared to a 'regular' 30ppm CO2 injection.
 
Hi all,
If we take this idea further then submerged plants utilizing bicarbonate have as much carbon available in aquariums with medium to high KH as in the nature under direct sunlight. We can't give them more KH unless we go for unusually hard cave water levels. So this is the maximum carbon they get under full sun.
We used to <"run an experiment"> to look at oxygen evolution <"using Cabomba caroliniana">, with dilute sodium bicarbonate (NaHCO3) as the <"inorganic carbon source">.

cheers Darrel
 
Hi all,
What do you think about them positioning the plants upside down during the test?
I'm not sure it really matters. You only get visible pearling once the plants internal spaces (<"lacunae and aerenchyma">) are saturated with oxygen and aquatic plants are very efficient at <"moving oxygen internally">. She talks about this from about 10:30 in the SAPS video. If you search for <"Radial Oxygen Loss"> it will give you some references.



Originally the experiment was done using the inverted funnel method, so I guess that was the original reason for using the plant inverted.

cheers Darrel
 
This research paper talks about higher CO2 levels inhibiting aquatic plant growth. Who would have thought?
The plant fragments were observed at different pH and CO2 levels, for only 30 minutes at each combination.
I do not think we can assume that we would see similar results in an aquarium situation.
We know that;
Plants can adapt to various conditions, within limits.
Plants take time (often more than 30mins) to adapt to new conditions.
Plant fragments do not always behave identically to whole plants.
 
MrTank, you posted an earlier tank shot where you said the CO2 was 40-50ppm . Could you post an updated full tank shot - is there any difference in plant growth between 40-50ppm and 150ppm?
sorry for my late reply to. Please forgive me. I am very new to the forum and my english is not very good.

To answer your question, I think too much co2 is not a good thing. I always had trouble. Growth stopped, coloration gone, I had a bacterial explosion.

Especially in difficult plants, deaths occurred. I still continue to experiment.

I wonder what will happen if I keep the fertilizer rate under 16000 lumens of light with very high co2. So I continue this experiment.
 

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very high CO2 maybe a good thing, I have no idea.

Problems I'm having:
1-bacteria growth stopped

2-Photosynthesis has stopped

3-Coloration is gone

4-Organic waste is very, very much.

5-Cionabacteria too much

Algae such as 6-SDA-GSA-BBA-GBA increased too much.

In fact, I think that the reason for all this is not CO2, and I could not adjust the fertilizer rate despite this high CO2.


I will keep trying.

I'm thinking of giving 10 ppm nitrate daily.

I apologize to everyone for my late reply. Unfortunately, I am having a very busy time.
 
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