Liquid CO2

[kc]

I saw Rainbow selling Liquid CO2 for $18. It consist of a bottle of maybe 50 - 90 cc in size and is mostly labled in Japanese so I can't tell much.

I think it's an interesting subject. Anybody using this?

[loupgarou]

probably similar to seachem excel

[Allen_1971]

I came across something similar in pet safari today... I would agree with chris... most likely its something similar to seachem excel

[talev]

Any idea what the solution's about?

Aquatic plants take in co2 either through emersed parts, carbonic acid (co2 injection) or [hc03]2 decalc. Since carbonic acid is rather volatile (as far as the co2 is concerned) and the bottle doesn't sound like it's airtight, i don't think it's carbonic acid. (Even if it was, it's like adding carbonated water to the tank. And adding it via the water surface merely forces the co2 out of solution even faster because osmotically it's easier for a gas to enter air than force its way into a denser medium like [co2 free] water).

If it's the bicarbonate or carbonate of some mineral than maybe this product is only useful for plants which can decalc efficiently. Although most plants can decalc, most need very high light to do so (dupla's toa, i think). And after decalc takes away the carbon, the hydroxide raises the ph. And because the dkh of the water is lowered, you get extreme ph swings. Not very good for fish?

[Allen_1971]

talev, mebbe you can take a read at seachems webby? Flourish excel is a similar product from seachem.

[DEA]

http://www.seachem.com/en_products/p...rsh_excel.html

enjoy [:]

[talev]

Thanks for the link.

This is a very long shot, so if any chemists can spot any boohoos please correct me.

The site claims excel contains polycycloglutaracetal. I have no idea what this is, except that it is a compound of carbon hydrogen oxygen and oxygen. (I know this doesn't help but wait). It sounds like another complex sugar, like glucose.

Some seachem guy gave an interview about excel http://www.aquabotanic.com/carbon.html in which he was careful not to reveal too much.

However, he mentioned that excel Flourish Excel "is
able to be utilized in the carbon chain building process of
photosynthesis... Simple chemical or enzymatic steps can easily convert
it to any one of the above named compounds (or a variety of others)," and that "algae can't feed on Excel", so I'm going to try to work it out from here.

Since algae can't use this carbon source, it should be something which is too complex to be broken down by algae. Most plants including algae are c3 type plants which in short means that they photosynthesise and take in carbon simultaneously. However, some plants can be considered to be c4 because they have mesophyll cells which can fix co2 independently of photosynthesis, and some plants have a crassulacean acid metabolism (cam) which allows the plant to fix co2 at night and store it for use in the day.

Both c4 and cam plants can therefore store their carbon source from the c4 sugars produced above, so plants which can do c4 or cam fixing almost never have carbon deficiency. Excel is likely to be a c4 sugar which contributes to the store of carbon in plants. And since cam is a very common trait among plants, and both c3 and c4 pathways can be found in many plants, maybe that's why the seachem people decided to give it a go. But don't ask me how the plant takes in the c4 sugar, cos i don't know.

[Allen_1971]

talev,

ok I'll be the first to admit I have almost no idea what you're talking about.

For starters, what are C3 and C4 plants... could you explain in terms my daughter would understand? Also are there C1 C2 plants?

[DEA]

you don't need a chemist
you need a plant biologist
can't help u there

[talev]

c3 simply means that co2 is fixed by the plant as 3 carbon sugars (3 c molecules in chain) in the calvin cycle.

Very crudely, the calvin cycle is the series of reactions which convert carbon into carbohydrates in plants.

c4 simply means that co2 is fixed as a 4 carbon sugar. The relevant difference here is that carbon for the calvin cycle in c4 plants come from c4 sugars instead of stomata intake.

There is no c1 and c2 btw.

[DEA]

glutaric acid is a 5 carbon dicarboxylic acid (aliphatic with terminal acid groups)
acetals are R2C(OR{prime})2
basically a ketone or aldehyde reacts with two alcohols, giving water and two RO groups attached to the carbon
what with the poly prefix, i think the flourish excel will have a lot more than 4 carbon
not sure about the structure of the whole thing tho

[Nicky]

This seemed to be an interesting thread and I have no idea what DEA and talev is talking about. But I like to know more cos I think this is very useful, can an interpreter pls step in?

[CK Yeo]

Without going into all the details of C3/C4/CAM metabolism I was rather curious to know if aquatic plants are C3 or C4 (or cam)?
I was under the impression that aquatic plants do not belong singly to any group (i.e there are examples of aquatic plants that are C3 or C4 or CAM.) Arguing that a 4-carbon sugar will benefit all plants is a far-far-shot.
For what it's worth, sucrose is used as a carbon source for plants that are in tissue culture. Why not just dump sucrose? Then, it saves the plants the trouble of fixing carbon in the first place. []

Second, I cannot understand how this carbon source be limited to higher plants and not algae. It is well-known that many aquatic plants can grab carbon from bicarbonate (so can algae, BTW). So is it an enzyme that after eyons of evolution, all higher aquatic plant found a way to break down a unconventional carbon source??

I cannot find anything from plant literature on polycycloglutaracetal, so I am not sure how it works (or if it works). Neither can I find it on sigma's database (chemical supplier)... if that is the case, I am really curious to know what is it or how does Seachem produce enough of it to make it available to the hobbyist market (but unavailable as a pure reagent to the professionals???? mind boggling...).

Finally, I am sure it is easier and cheaper to just inject gaseous CO2 from cylinder, DIY fermentation or even electrolysis. BTW, does anyone knows of anyone who keeps a stunning plant tank using this stuff? I guess this is the easiest way to tell if it works.

ck

[talev]

To cut it very short, what i'm trying to say is that

- some plants don't have to take in co2 at the same time or place as photosynthesis. (c4 and cam plants)

- these c4 and cam plants fix carbon dioxide separately from photosynthesis (either in time or spatially) and store them up as c4 sugars, for use during light hours. c4 and cam plants therefore almost never have co2 shortages.

- excel seems to be a product which aims to top up the plants' supply of c4 sugars.

- there are other conjectures on the net which suggest that excel functions as a tannin which in small quantities act as a chelator and in large quantities as a disinfectant, but i don't think these are the main purposes of excel. After all, if a metal has already oxidised, chelating it won't bring it back into the assmilable state.

[talev]

Without going into all the details of C3/C4/CAM metabolism I was rather curious to know if aquatic plants are C3 or C4 (or cam)?

If you are asking about all aquatic plants as a broad whole then i honestly do not know.

IMHO this does not really matter, because both c3 and c4 pathways have been found to be used in the same plants in varying degrees.

I was under the impression that aquatic plants do not belong singly to any group (i.e there are examples of aquatic plants that are C3 or C4 or CAM.) Arguing that a 4-carbon sugar will benefit all plants is a far-far-shot.

You are right. If you haven't caught it yet my ambitious shot was to label algae incapable of c4 assmilation. No one has proved this yet as far as i know, probably because one day algae will adapt (again).

I never suggested that a 4c sugar will benefit all plants. In fact, the active ingredient in excel appears to be a 5c sugar. Some (primitive) plants incapable of c4 assmilation will probably suffer. But like I mentioned earlier, it is common to find plants capable of using c3 and c4 assimilation.

For what it's worth, sucrose is used as a carbon source for plants that are in tissue culture. Why not just dump sucrose? Then, it saves the plants the trouble of fixing carbon in the first place. []

I was thinking of that. But some seachem bloke has vigorously denied any similarities between the active ingredient and other complex but common sugars. Maybe it's deceptive shielding of the true id of the active ingredient.

Second, I cannot understand how this carbon source be limited to higher plants and not algae. It is well-known that many aquatic plants can grab carbon from bicarbonate (so can algae, BTW). So is it an enzyme that after eyons of evolution, all higher aquatic plant found a way to break down a unconventional carbon source??

Do algae (freshwater) have mesophyll cells?

I cannot find anything from plant literature on polycycloglutaracetal, so I am not sure how it works (or if it works). Neither can I find it on sigma's database (chemical supplier)... if that is the case, I am really curious to know what is it or how does Seachem produce enough of it to make it available to the hobbyist market (but unavailable as a pure reagent to the professionals???? mind boggling...).

I agree. Denial of the active ingredient as a complex sugar is suspicious enough. I've got absolutely nothing against seachem, but the poly************ could be a name coined up to hide the real ingredient.

Finally, I am sure it is easier and cheaper to just inject gaseous CO2 from cylinder, DIY fermentation or even electrolysis. BTW, does anyone knows of anyone who keeps a stunning plant tank using this stuff? I guess this is the easiest way to tell if it works.

Yes. If everyone stuck to easier ways of providing carbon this tedious discussion wouldn't have been necessary. There are a few testimonials on the net. Almost all are low light and 'hanging on the cliff' tanks.

[CK Yeo]

[quote]
----------------
On 12/27/2002 8:02:26 PM

If you are asking about all aquatic plants as a broad whole then i honestly do not know. IMHO this does not really matter, because both c3 and c4 pathways have been found to be used in the same plants in varying degrees.

But if we dun know if we are talking about C3/C4/CAM, then discussion of how something might work as a carbon source would purely be speculative and IMHO, pointless.

I understand that people have engineered to make C3 plants to become C4-like. It is not just the structure between C3 and C4 (bundle shealth actually), one or two enzyme in C4 plants is missing in the C3 plants (can't remember the details, it was something on corn and rice).

You are right. If you haven't caught it yet my ambitious shot was to label algae incapable of c4 assmilation. No one has proved this yet as far as i know, probably because one day algae will adapt (again).

Well, it will need more evidence from scientific community to show that algae can't take in 4 carbon sugar (I suspect they can, but what for?), though I cannot see the advantage of algae working on 4-carbon sugar when it can get it from HCO3.

I never suggested that a 4c sugar will benefit all plants. In fact, the active ingredient in excel appears to be a 5c sugar. Some (primitive) plants incapable of c4 assmilation will probably suffer. But like I mentioned earlier, it is common to find plants capable of using c3 and c4 assimilation.

the 5th carbon is a COOH somewhere?

I was thinking of that. But some seachem bloke has vigorously denied any similarities between the active ingredient and other complex but common sugars. Maybe it's deceptive shielding of the true id of the active ingredient.

In case anyone is going to try adding sucrose to their tanks, dun. Sugar will promote a bloom in bacteria and make the water cloudy, besides producing CO2. Could bacteria decomposition be really how Seachem's magic potient works?

Do algae (freshwater) have mesophyll cells?

No. but what is your point? Do you mean bundle shealths instead? How does absence of mesophyll cells affect the algae cell ability to take it a 4 carbon sugar? There are no membrane transporters for it? Too big for algae cell wall but ok for mesophyll cells? A missing enzyme to convery 4 carbon sugar to 3 carbon? We really dun know, do we?

I agree. Denial of the active ingredient as a complex sugar is suspicious enough. I've got absolutely nothing against seachem, but the poly************ could be a name coined up to hide the real ingredient.

Is starch complex enough? How about glycogen? We can go on forever...

Yes. If everyone stuck to easier ways of providing carbon this tedious discussion wouldn't have been necessary. There are a few testimonials on the net. Almost all are low light and 'hanging on the cliff' tanks.

Exactly. So other than an entertaining, fun, hearty discussion on plant physiology, I seriously doubt that this product will become the mainstream of plant tank enthusiatist.

So to the original poster, dun bother with it, you will have better luck with DIY CO2, unless your aim is for "low light and 'hanging on the cliff' tanks."

ck

[loupgarou]

I use fluorish excel, but i have no control tank against to compare since I also use co2 injection, I'll be taking the bottle to the office to put in my no light, no co2 tenellus tank 10x10x10.

one thing though, excel has a particular acrid smell to it reminscent of formaldehyde ...

[talev]

But if we dun know if we are talking about C3/C4/CAM, then discussion of how something might work as a carbon source would purely be speculative and IMHO, pointless.

Exactly. My discussion was never meant as a thoroughly supported thesis. It was my shot in the dark. This product also probably is.

Well, it will need more evidence from scientific community to show that algae can't take in 4 carbon sugar (I suspect they can, but what for?), though I cannot see the advantage of algae working on 4-carbon sugar when it can get it from HCO3.

Which may be why the seachem guy claimed algae can't benefit from excel. But wouldn't it take more energy to take c out of hco3 via decalc (assuming it can) and then convert it into sugars when it can simply take in the sugar?

In case anyone is going to try adding sucrose to their tanks, dun. Sugar will promote a bloom in bacteria and make the water cloudy, besides producing CO2. Could bacteria decomposition be really how Seachem's magic potient works?

You've hit the nail on the head. Overdosing of excel DOES and will cause a bacteria bloom. So... it does seem that excel indeed contains a sugar not unlike sucrose and the like.

Exactly. So other than an entertaining, fun, hearty discussion on plant physiology, I seriously doubt that this product will become the mainstream of plant tank enthusiatist.

Yes. Discussions like this should be left behind lab walls, because when they're brought out into the hobby somehow things become more complicated and tedious than they should be.

[DEA]

acetals tend to smell like that

anyway, the long and short of it for the benefit of the original poster is : no one knows exactly how it works, or has done tests on how well it works

what i've noticed in the past is it does
even causing bubbling without co2 injection (ie, bubbling occured only after the addition of excel)

don't worry about all the c3/c4/cam stuff
not important for our purposes

what i can say for you is, try it out
if you like the effect, you can go on using it
but nothing will be more efficient than pressurised co2