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Stable CO2

With regards the question of stable CO2. I think folk sometimes confuse unstable with unavailable. My understanding is that plants will adapt to their environment or ultimately die. For instance, plants used to a low-energy environment will adapt accordingly and compete to use up available CO2 at the beginning of the photoperiod. In this case the CO2 is not unstable it is just not available throughout the entire photoperiod.

I guess it's a good question to ask "What are the criteriums for unstable CO²?" I find the term unstable CO² rather confusing in it self. And in many threads at the end, it becomes even more confusing because there are so many individuals takes on it.

But it must be possible to narrow it down in a simple summary everybody can understand.

To give a short summary my best guess.

stable CO² =

1: A stable bubble count during the entire cycle.
2: A lime green drop checker at lights on.
3: Sufficient distribution/flow.
4: A good quality diffuser.
5: ? or more?

Then if one of these is not met, results in an unstable CO² distribution with all its consequences... :)
 
Rubisco Wkii , Rubisco, Rubisco - worth a read IMO

Quote
Rubisco is an enzyme involved in the first major step of carbon fixation, a process by which the atmospheric carbon dioxide is converted by plants and other photosynthetic organisms to energy-rich molecules such as glucose.

Some enzymes can carry out thousands of chemical reactions each second. However, RuBisCO is slow, fixing only 3-10 carbon dioxide molecules each second per molecule of enzyme. The reaction catalyzed by RuBisCO is, thus, the primary rate-limiting factor of the Calvin cycle during the day. Nevertheless, under most conditions, and when light is not otherwise limiting photosynthesis, the speed of RuBisCO responds positively to increasing carbon dioxide concentration.RuBisCO is usually only active during the day as ribulose 1,5-bisphosphate is not regenerated in the dark.

In spite of its central role, rubisco is remarkably inefficient. As enzymes go, it is painfully slow. Typical enzymes can process a thousand molecules per second, but rubisco fixes only about three carbon dioxide molecules per second. Plant cells compensate for this slow rate by building lots of the enzyme. Chloroplasts are filled with rubisco, which comprises half of the protein. This makes rubisco the most plentiful single enzyme on the Earth.

Unquote

So this fit the model of having a stable [CO2] during the main photoperiod, as rubisco is not generated in the dark - Which is what Clive tells us- So the pH spike at night is irrelevant


IMO appling Liebigs law enables us to have an unstable [CO2] and no issues ' in theroy'. As if the [CO2] is none limiting at any given time, then rubisco works faster (from above quote) , the 'expensive' production of Rubisco will not be needed 'as much' by the plant, and will not need to increase its Rubisco production therefore the [CO2] is irrelevant as long as CO2 is non Limiting.

But it must be possible to narrow it down in a simple summary everybody can understand.

Sometimes it takes years of study to to understand some things as the complete pathway can/is quite complex and a simplification of it just doesn't do it justice :rolleyes:
 
IMO appling Liebigs law enables us to have an unstable [CO2] and no issues ' in theroy'. As if the [CO2] is none limiting at any given time, then rubisco works faster
or at least maintain a conc. where limits to growth and competition between plants doesn't occur. Which is more to the point.


I guess it's a good question to ask "What are the criteriums for unstable CO²?"
If however the CO2 conc. is inconsistent or unstable, in that it varies, throughout the photoperiod and from one day to the next,
:)
 
Sometimes it takes years of study to to understand some things as the complete pathway can/is quite complex and a simplification of it just doesn't do it justice

Well, then it seems more complex than tools available to determine CO² stability. :rolleyes:

Makes it rather unexplainable, since you can't teach experience...
 
If you can offer alternatives I am sure many folk would be delighted find out how?
That is very well put foxfish. I'd certainly like to know more.
 
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This is what “he” propagates on “other forums”:

“Low CO2 does no harm and is not critical in any way on its own. ADA tanks are evidence of this as well as my own experiments in my tanks. You can actually grow a nice tank in high light intensities without adding any CO2; it's a myth that high light requires high CO2. If the concentration of metals fall into the toxic range, that's when plants will have difficulty growing and maintaining good health. If the concentration is too far into the toxic range, no amount of CO2 coupled with high light intensities will alleviate it.“ - end quote

Now we know ADA tanks have very low light intensities (being tested in person with a par meter by Tom) and they also have the entire Japanese reserve army to keep the tanks clean of any algae at any given time of the day.

We also know by now high light and no co2 is a recipe for disaster, an algae soup very easily replicated over and over again.

I choose to go on with high co2 high flow and high fertilizers with lower light levels ....and get results.
 
We also know by now high light and no co2 is a recipe for disaster

Could be, but not necessarily...

As stated before i experience the contrary each year again the last 3 summers and the 4th is coming and i don't expect it to be any different.

1th year, full blast sunshine all day long not 1 minute shade even on a rainy day it got more lumens than any lamp could provide, 0 algae, 0 fertilizer, natural CO² equilibrium. Super healthy plant growth.
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2th year exact same setup, same substrate, didn't change a thing, same regime, same story but some different plants. See the Lilaeopsis carpet.
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3rd year.
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Disaster? Yes it was a disaster to trim the plants... :eek::p

It seems there are no answers only statements and even more questions...

And not to make a statement but an assumption, a part believing without evidence. :)

As said before it is what you see is what you get.. Proof in the pudding? I simply can not tell you why.

I must add, don't be fooled by its size, this little aquarium is hooked to a 350 litre planted sump.

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1th year, full blast sunshine all day long not 1 minute shade, 0 algae, 0 fertilizer, natural CO² equilibrium. Super healthy plant growth.
I think 0 fertz is probably key. I'm guessing the substrate had enough nutrients to feed the plants. And we also know that high density plant biomass infers a great deal of biological stability. And the floating plants would quickly soak up any excess, starving algae. I know Darrel @dw1305 has high light low-energy tanks using a similar principle, with lots of floating plants.

I experimented with this a few years back now. 2xT5 HO lights over a densely planted low-energy with minimal fertz input, most of the nutrients in the soil. And it remained remarkably algae free for several months. I think the ADA system isn't that far removed from this also. Very nutrient rich soil and lean dosing. Filipe Olivera also uses a very similar technique.

It doesn't really contradict what we already know, and like I mentioned before the CO2 conc. isn't unstable just unavailable for part of the photoperiod. Some plants will adapt very well to this environment since they use other pathways to synthesise carbon, e.g. vallis is very good as using bicarbonates.

High light, low-energy, soil substrate tank
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The substrate used was 4 litres Velda Lelite Blue clay, the rest river sand and gravel. And it kept up for 3 years now...

This year i'm planning to strip it and do something different.. Not yet decided what..

Any suggestions? I'm in for a new experiment. :)
 
How about planting a few swords? It'd be nice to see some slightly more exotic looking emergent growth and maybe flower spikes :)
Is a new mission imminent?
 
How about planting a few swords? It'd be nice to see some slightly more exotic looking emergent growth and maybe flower spikes :)
Is a new mission imminent?

Absolutely imminent. :)

That is a nice idea. Thanks Tim... I can imagine it looking great, planting a variety of swords in it..

Tho i have a few Swords (Kleiner Bär) in the tub from the start and experience them problematic surviving the winter indoors. Planted them on an inert substrate (frit glass), they grow well in the summer but wither away again in the winter indoors and then i have to start over from scratch again. Due to light deficiency i guess. Or a combination of light and fertilization. Till now they came back each year again, but never really very strong.

I could give it a go, to plant them in this tank on a heavy clay substrate and see if it makes a stronger plant with more mass at the summer's end. An experiment well worth a try...

Have to do some reading about the best varieties i can choose from... Flowgrow has a complete thread on growing them emerged "<The Year Of Echinodorus>". It's loaded with pictures about growing them in the garden. There i'll find my answers.. :)

Bellow an old picture from a few years back, all other years it got completely overgrown with other plants.
 

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Could be, but not necessarily...
Zozo not to be contradictory I’m just raising some questions. I see some piping next to the tank feeding water to it. Is that some sort of continuous fresh water supply?
Have you ever tested your tap? What’s it like? We see high PO4 and NO3 straight out of the tap in some areas of the world while other areas are completely depleted of them.
The statement that no other lamp could provide what the sun provides in terms of light intensity is I’m afraid not in line with reality.
I burned many SPS corals in my system over the years and others have done the same because of too much light (350-500 PAR at the upper 1/3rd of the tank) yet they remain in great shape in the Great Barrier Reef unless very high ocean temperatures trigger a mass bleaching.
What I’m trying to say is yes artificial light can be more intense than natural light .
Your outdoor tank doesn’t tell us the whole story with statements like “no nutrients and more light than any indoor lamp”.
Then we have the natural path the sun follows with the most intense output just for a few short hours, the rest is less so. Most of indoor tanks (more so the ones having issues) just blast the plants for 7-9 hours with high light continuously ; there’s rarely any ramp up and down of the light to mimic natural setting.
Clive implements it in his tank and his statement made a lot of sense; plants need a little time to get up and go just like we need time when we wake up to get dressed eat breakfast then go to work.

Again, it would be nice to know the source of your water and parameters and if you could have access to a PAR meter to put some numbers on those claims.
Not disapproving of your method, just that we need factual statements before drawing any real conclusions.
 
Personally I just run my co2 24/7 at a slow steady rate, I only grow slow growing easy plants, that probably dont need co2 but I find it just helps keep everything stable, I also dont use any nutrients these days and the tank is fairly algae free

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untitled-2366.jpg by Colm Doyle, on Flickr
 
Your outdoor tank doesn’t tell us the whole story with statements like “no nutrients and more light than any indoor lamp”.

I didn't state "No Nutrients" :) I said "No Fertilizer" and that is something completely different... Obviously the plant needs nutrients to live and likely got some nutrients from something, from the clay substrate, fish poop, any other natural means the water column brings them. I do not add anything extra on top.

And for so far, i should have said any indoor lamp available to my budget yet can't compete with what the sun provides.
I'm not aware of any product that claims to be equal or stronger than the Sun... :) Indeed that and my doubts don't say it isn't out there. You got me on that one... :thumbup: But i guess if it exists you have to reach very very deep into your pocket to obtain it as a hobbyist. And need some darn good sunglasses while watching your tank.

I see some piping next to the tank feeding water to it. Is that some sort of continuous freshwater supply?

Nope, It's an old Zinc bathtub and a sort of aquaponic filter and a little aquarium hooked together. Approximately 350 litres, it's a closed system that needs an occasional water change if i like to add fresh water. And if then this is Tapwater which is pretty soft gH4 / kH10.
>20 mg/l NO³ and 0 PO4.

I have no access to PAR meters i probably never will have, it's out of my budget and comfort zone of interest. And from what i understand even if i would have, it still wouldn't be a conclusive number. Because from what i understand from very knowledgeable botanists working in this field. We actually need to know the PPFD before PAR says something.

I'm trying not to make statements and even fewer claims. For the biggest part the conclusion i draw to myself is, i don't really know. That's why i simply share an experience and say "It's what you see is what you get." and i can't tell you why. It is what it is... :)
 
Zozo not to be contradictory I’m just raising some questions.

I think we are all on the same page i.e.we are having a discussion aka peer review, no body is saying these are the facts and we are all open minded on the subject ;)

The statement that no other lamp could provide what the sun provides in terms of light intensity is I’m afraid not in line with reality.

Think @Andrew T has made a very valid point here esp we consider Reflection and Refraction with our tanks with fixed lights the incident angle is constant so the light intensity will be constant if the lights output remains constant. However with natural light the incident angle of the light will be constantly changing as well as the light intensity, also the incident angle will change on a daily basis as the sun climbs/falls in the sky. So maybe our fixed lights above our tanks do bombard our plants with more photons than a tank receiving natural daylight light in a single photoperiod, not says always do, but maybe more than with think :angelic:
 
I found a report from a meteorology institute with sunlight Lux measurements somewhere in the average middle of my country, which is approximately for the biggest part situated 5 metres below sea level. This would mean the same measurement done at places above sea level would give higher numbers. Since at the top of one of world's highest accessible mountains it's measured 5 x higher.

The report doesn't say day time and date but we can assume it's an average throughout clear sky days.

Results are:
Direct sunlight: 130 000 lux
Indirect - Daylight: 20 000 lux

Compared to a Phillips HPI-T Grow light 1000 watts Metal Halide = 85000 lumen

Lux = Lumen/m², Correct? Meaning in case of artificial light according to the height of the lamp placed above the surface it should illuminate means less lumen/m².

Actually no idea how it relates exactly and how Phillips measured it, i guess to put it in a reflector and make it illuminate 1m² exact and take some Lux measurements. At whatever. a height that maybe. Anyway a pretty darn beast of a lamp not yet coming close.

Another experience i did that made me wonder. I once had a lily flowering in of my at the time High Tech aquarium in the month November. It was illuminated with about 10.000 lumens LED fixture x 50cm above the tank. And daylight flowering lilies, close their flowers when its getting dark.
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The fun part that baffled me was... The tank stood 1 metre next to a North-East facing window receiving a tad indirect daylight. The lights were on till 9 pm, but the sunset was at around 6pm. And despite the LED lights still operating at 100% at 6pm the Lily flower closed 3 hours to early. It didn't react to the artificial light but rather to the indirect daylight from outside.

Made me scratch behind me ears and wonder what is in the light? Why does my Lily flower prefer the low natural daylight during wintertime above my 10.000 lumen LED fixture?

I don't know, it just did.

Was it the intensity or is artificial light missing some parts of the spectrum the plant reacts to? It beats me and knocks me off my shoes..
Another what you see is what you get mystery. :)
 
[QUOTE="zozo, post: 592866, member: 13448"
]Direct sunlight: 130 000 lux
Compared to a Phillips HPI-T Grow light 1000 watts Metal Halide = 85000 lumen[/QUOTE]

So sunlight is double the Metal Halide but relatively the same order of magnitude

Light penetration into fresh water

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So therefore the light absorption coefficients will be higher in our tanks with artificial light compare to natural sunlight due to the incident angle of the light source.

So I would wouldn't be surprised if the Grow light 1000 watts Metal Halide yield more lux/PAR then natural sunlight at any given depth in our tanks and the incident angle of the metal halide is constant, but the sunlight is variable though out the day so the net light will also be greater with the metal halide also.
 
Hi all,
I'm pretty sure that light intensity at midday in the tropics is going to be an order of magnitude larger than anything that we can produce with a lamp. I'll try and find a reference that quotes the different measures of light intensity. For sunlight you should be able to equate light intensity with PAR.

cheers Darrel
 
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