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#1
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Languishing Paphiopedilum
I have a Paph. Transcolor that has not been growing well for a year
and a half. It was in a bark mix in a 5in plastic pot until 6 months ago, repooted 6 months before that. I now have it in a coconut husk mix in a 5 inch clear pot. The coconut mix is the one that I use for all of my Paphs. ala Antec The roots look good, they have grown since repotting. I tapped out some of the mix and the roots are firm and fuzzy like they should be. The three crowns of the plant have continued to grow, but they have lost larger outer leaves in favor of smaller inner ones. The leaves are waxy and small and light colored and they keep growing and the outer ones keep falling! This is a picture of the flowers and leaves of the second blooming after I purchased it. (It was purchased in bloom, it bloomed again 6 months later, and then this blooming, its last in two years.) http://members.verizon.net/~vze4xcmt...transcolor.jpg I grew it in an east window indoors up until this fall. I tried moving it under lights with the rest of my collection to see if that would help, still no signs of improvement. Thanks, Jim |
#2
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Languishing Paphiopedilum
Germ,
Interesting problem! You say that the roots are healthy and growing which is the first suspect in a mystery such as this. 5 inch pot sounds a bit large but you didn't state the leaf spread so I can't say for sure. But since the roots are growing well I assume this is not the issue. You mention the larger leaves are dropping and new smaller ones are replacing them. I see this when a plant gets too much light and is stressed. Doesn't sound like light is your issue since you moved the plant under lights and before that it was in an east window. Hmmmm (could it be the butler in the library with the candlestick?) What a mystery....maybe it's the potting mix? no, you said you are using it for other paphs. Maybe the plant needs something you're not giving it? Is this one of the paphs that need calcium in the mix? If this is the case the change of mix would explain why it grew for a while and then started to fail. Check the plant's parentage and see if it has calcelious (I can't spell) .....parents that need calcium in their mix to enable them to take up nutrients. Let us know what you find out. Good Growing, Gene "germ" wrote in message m... I have a Paph. Transcolor that has not been growing well for a year and a half. It was in a bark mix in a 5in plastic pot until 6 months ago, repooted 6 months before that. I now have it in a coconut husk mix in a 5 inch clear pot. The coconut mix is the one that I use for all of my Paphs. ala Antec The roots look good, they have grown since repotting. I tapped out some of the mix and the roots are firm and fuzzy like they should be. The three crowns of the plant have continued to grow, but they have lost larger outer leaves in favor of smaller inner ones. The leaves are waxy and small and light colored and they keep growing and the outer ones keep falling! This is a picture of the flowers and leaves of the second blooming after I purchased it. (It was purchased in bloom, it bloomed again 6 months later, and then this blooming, its last in two years.) http://members.verizon.net/~vze4xcmt...transcolor.jpg I grew it in an east window indoors up until this fall. I tried moving it under lights with the rest of my collection to see if that would help, still no signs of improvement. Thanks, Jim |
#3
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Languishing Paphiopedilum
Good thinking Gene, you could be right. Wildcatt lists Paph Transcolor
as 50% concolor, 25% rothschildianum, and 25% chamberlainianum. Concolor is of course calcicolous and rothschildianum is not. I had to look up the 3rd ancestor. I found this web site: http://www.angelfire.com/or3/orchids...hlopetalum.htm which contains this quote: "Growing on limestone cliff faces near running creeks, and in water seepage zones, it sought thick pads of humus and leaf detritus which had accumulated against tree roots. While growing in limestone, Fowlie notes they should not be cultivated on limestone chips, as the cooler water of our temperate climates would allow greater dissolution of the limestone particles, possibly furnishing toxic levels of calcium to the plants. Naturally it receives bright but not direct sunlight." I guess Transcolor is mostly calcicolous and should be supplemented with lime in some form. I use a top dressing of crushed oyster shell, myself. Steve in the Adirondacks of northern NY Gene Schurg wrote: Germ, Interesting problem! You say that the roots are healthy and growing which is the first suspect in a mystery such as this. 5 inch pot sounds a bit large but you didn't state the leaf spread so I can't say for sure. But since the roots are growing well I assume this is not the issue. You mention the larger leaves are dropping and new smaller ones are replacing them. I see this when a plant gets too much light and is stressed. Doesn't sound like light is your issue since you moved the plant under lights and before that it was in an east window. Hmmmm (could it be the butler in the library with the candlestick?) What a mystery....maybe it's the potting mix? no, you said you are using it for other paphs. Maybe the plant needs something you're not giving it? Is this one of the paphs that need calcium in the mix? If this is the case the change of mix would explain why it grew for a while and then started to fail. Check the plant's parentage and see if it has calcelious (I can't spell) .....parents that need calcium in their mix to enable them to take up nutrients. Let us know what you find out. Good Growing, Gene "germ" wrote in message m... I have a Paph. Transcolor that has not been growing well for a year and a half. It was in a bark mix in a 5in plastic pot until 6 months ago, repooted 6 months before that. I now have it in a coconut husk mix in a 5 inch clear pot. The coconut mix is the one that I use for all of my Paphs. ala Antec The roots look good, they have grown since repotting. I tapped out some of the mix and the roots are firm and fuzzy like they should be. The three crowns of the plant have continued to grow, but they have lost larger outer leaves in favor of smaller inner ones. The leaves are waxy and small and light colored and they keep growing and the outer ones keep falling! This is a picture of the flowers and leaves of the second blooming after I purchased it. (It was purchased in bloom, it bloomed again 6 months later, and then this blooming, its last in two years.) http://members.verizon.net/~vze4xcmt...transcolor.jpg I grew it in an east window indoors up until this fall. I tried moving it under lights with the rest of my collection to see if that would help, still no signs of improvement. Thanks, Jim |
#4
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Languishing Paphiopedilum
Sorry to disagree, in part, Steve,but Fowlie is wrong. The only chemicals
(barring a few weirdos) that dissolve better in cooler temps than warm ones are gases such as oxygen. Calcium compounds are notoriously insoluble except in acids. Therefore acid water could cause a toxic buildup. Or using acidic peat moss could have the same effect, but not in neutral coconut. I'd say limestone marble chips would be great with coconut for the calceocolous paphs (but I haven't tried it - yet. Good idea though.) Gary "Steve" wrote in message ... Good thinking Gene, you could be right. Wildcatt lists Paph Transcolor as 50% concolor, 25% rothschildianum, and 25% chamberlainianum. Concolor is of course calcicolous and rothschildianum is not. I had to look up the 3rd ancestor. I found this web site: http://www.angelfire.com/or3/orchids...hlopetalum.htm which contains this quote: "Growing on limestone cliff faces near running creeks, and in water seepage zones, it sought thick pads of humus and leaf detritus which had accumulated against tree roots. While growing in limestone, Fowlie notes they should not be cultivated on limestone chips, as the cooler water of our temperate climates would allow greater dissolution of the limestone particles, possibly furnishing toxic levels of calcium to the plants. Naturally it receives bright but not direct sunlight." I guess Transcolor is mostly calcicolous and should be supplemented with lime in some form. I use a top dressing of crushed oyster shell, myself. Steve in the Adirondacks of northern NY Gene Schurg wrote: Germ, Interesting problem! You say that the roots are healthy and growing which is the first suspect in a mystery such as this. 5 inch pot sounds a bit large but you didn't state the leaf spread so I can't say for sure. But since the roots are growing well I assume this is not the issue. You mention the larger leaves are dropping and new smaller ones are replacing them. I see this when a plant gets too much light and is stressed. Doesn't sound like light is your issue since you moved the plant under lights and before that it was in an east window. Hmmmm (could it be the butler in the library with the candlestick?) What a mystery....maybe it's the potting mix? no, you said you are using it for other paphs. Maybe the plant needs something you're not giving it? Is this one of the paphs that need calcium in the mix? If this is the case the change of mix would explain why it grew for a while and then started to fail. Check the plant's parentage and see if it has calcelious (I can't spell) ......parents that need calcium in their mix to enable them to take up nutrients. Let us know what you find out. Good Growing, Gene "germ" wrote in message m... I have a Paph. Transcolor that has not been growing well for a year and a half. It was in a bark mix in a 5in plastic pot until 6 months ago, repooted 6 months before that. I now have it in a coconut husk mix in a 5 inch clear pot. The coconut mix is the one that I use for all of my Paphs. ala Antec The roots look good, they have grown since repotting. I tapped out some of the mix and the roots are firm and fuzzy like they should be. The three crowns of the plant have continued to grow, but they have lost larger outer leaves in favor of smaller inner ones. The leaves are waxy and small and light colored and they keep growing and the outer ones keep falling! This is a picture of the flowers and leaves of the second blooming after I purchased it. (It was purchased in bloom, it bloomed again 6 months later, and then this blooming, its last in two years.) http://members.verizon.net/~vze4xcmt...transcolor.jpg I grew it in an east window indoors up until this fall. I tried moving it under lights with the rest of my collection to see if that would help, still no signs of improvement. Thanks, Jim |
#5
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Languishing Paphiopedilum
Gary,
Are you sure about that? Limestone is calcium carbonate, and is quite soluble in water. That's mostly what makes folks' water "hard." If I remember my CRC Handbook lookups, calcium carbonate is more soluble in cold than warm water. I could be wrong - I haven't looked it up in a long time... -- Ray Barkalow First Rays Orchids http://www.firstrays.com Secure Online Ordering & Lots of Free Info! "Gareth Wills" wrote in message ... Sorry to disagree, in part, Steve,but Fowlie is wrong. The only chemicals (barring a few weirdos) that dissolve better in cooler temps than warm ones are gases such as oxygen. Calcium compounds are notoriously insoluble except in acids. Therefore acid water could cause a toxic buildup. Or using acidic peat moss could have the same effect, but not in neutral coconut. I'd say limestone marble chips would be great with coconut for the calceocolous paphs (but I haven't tried it - yet. Good idea though.) Gary "Steve" wrote in message ... Good thinking Gene, you could be right. Wildcatt lists Paph Transcolor as 50% concolor, 25% rothschildianum, and 25% chamberlainianum. Concolor is of course calcicolous and rothschildianum is not. I had to look up the 3rd ancestor. I found this web site: http://www.angelfire.com/or3/orchids...hlopetalum.htm which contains this quote: "Growing on limestone cliff faces near running creeks, and in water seepage zones, it sought thick pads of humus and leaf detritus which had accumulated against tree roots. While growing in limestone, Fowlie notes they should not be cultivated on limestone chips, as the cooler water of our temperate climates would allow greater dissolution of the limestone particles, possibly furnishing toxic levels of calcium to the plants. Naturally it receives bright but not direct sunlight." I guess Transcolor is mostly calcicolous and should be supplemented with lime in some form. I use a top dressing of crushed oyster shell, myself. Steve in the Adirondacks of northern NY Gene Schurg wrote: Germ, Interesting problem! You say that the roots are healthy and growing which is the first suspect in a mystery such as this. 5 inch pot sounds a bit large but you didn't state the leaf spread so I can't say for sure. But since the roots are growing well I assume this is not the issue. You mention the larger leaves are dropping and new smaller ones are replacing them. I see this when a plant gets too much light and is stressed. Doesn't sound like light is your issue since you moved the plant under lights and before that it was in an east window. Hmmmm (could it be the butler in the library with the candlestick?) What a mystery....maybe it's the potting mix? no, you said you are using it for other paphs. Maybe the plant needs something you're not giving it? Is this one of the paphs that need calcium in the mix? If this is the case the change of mix would explain why it grew for a while and then started to fail. Check the plant's parentage and see if it has calcelious (I can't spell) .....parents that need calcium in their mix to enable them to take up nutrients. Let us know what you find out. Good Growing, Gene "germ" wrote in message m... I have a Paph. Transcolor that has not been growing well for a year and a half. It was in a bark mix in a 5in plastic pot until 6 months ago, repooted 6 months before that. I now have it in a coconut husk mix in a 5 inch clear pot. The coconut mix is the one that I use for all of my Paphs. ala Antec The roots look good, they have grown since repotting. I tapped out some of the mix and the roots are firm and fuzzy like they should be. The three crowns of the plant have continued to grow, but they have lost larger outer leaves in favor of smaller inner ones. The leaves are waxy and small and light colored and they keep growing and the outer ones keep falling! This is a picture of the flowers and leaves of the second blooming after I purchased it. (It was purchased in bloom, it bloomed again 6 months later, and then this blooming, its last in two years.) http://members.verizon.net/~vze4xcmt...transcolor.jpg I grew it in an east window indoors up until this fall. I tried moving it under lights with the rest of my collection to see if that would help, still no signs of improvement. Thanks, Jim |
#6
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Languishing Paphiopedilum
Gareth Wills wrote: Sorry to disagree, in part, Steve,but Fowlie is wrong. The only chemicals (barring a few weirdos) that dissolve better in cooler temps than warm ones are gases such as oxygen. Calcium compounds are notoriously insoluble except in acids. Therefore acid water could cause a toxic buildup. Or using acidic peat moss could have the same effect, but not in neutral coconut. I'd say limestone marble chips would be great with coconut for the calceocolous paphs (but I haven't tried it - yet. Good idea though.) Gary Yeah, that sounded weird to me too. I didn't think about it too much and just copied the entire paragraph. I should have just left that part out. Steve |
#7
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Languishing Paphiopedilum
Yes, calcium carbonate, unlike most substances, tends to be more soluble
in cooler water. However, its not so soluble that cool water will dissolve a toxic amount of calcium. I use oyster shell on calcium loving paphs, even with my coconut chips. For some, like parvi's and brachy's, I include large marble chunks at the bottom of the pot...hopefully simulating a more natural situation where roots contact limestone/marble/dolomite under the organic material..Take care, Eric Muehlbauer...fanaticum opening while emersonii is taking its sweet time.... |
#8
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Languishing Paphiopedilum
I realized that a concolor hybrid should have some lime in the mix. I
gave it as much crushed oyster shell as my malopoense and armeniacum. I found this looking today: http://www.ladyslipper.com/calsub.htm I am going to repot it again. I will use marble chips in place of the large alifor in the mix. I cannot think of anything else to do! Thanks for the comments. |
#9
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Languishing Paphiopedilum
"Gareth Wills" spaketh thusly:
Sorry to disagree, in part, Steve,but Fowlie is wrong. The only chemicals (barring a few weirdos) that dissolve better in cooler temps than warm ones are gases such as oxygen. Calcium compounds are notoriously insoluble except in acids. Then, unfortunately for your system, you are going to have to lump calcium carbonate in with the "few weirdos" as its solubility decreases as temperature increases. I base my claims as regards to this paradox on statements made in two separate copies of the CRC Handbook of Physics and Chemistry, my attending graduate school in stable isotope geochemistry (even if I wasn't all there at the time), and perhaps most importantly, the laws of physics and chemistry. Poor, neglected calcium carbonate, every caver's best friend. The solubility of calcium carbonate is tied to the concentration of the bicarbonate anion, which is present in solution in low concentrations thanks to atmospheric carbon dioxide. An increase in the temperature causes carbon dioxide to become less soluble in solution and, along with it, the solubility of calcium carbonate also decreases. You may thank LeChatelier's Principle for this (although, if you wish to thank me instead, 20's and 50's are welcome- send them to your local high school chemistry teacher). An excellent primer, if you're bored to death, is found he http://members.aol.com/profchm/comonion.html Back to carbonate solubility! Behold! The caver's formula: CO2 + H20 -- H2CO3 Carbon dioxide plus water gives you carbonic acid. Carbonic acid loses its first proton- a moment we should all pause to reflect upon, but not he privately. When you're done, come back; we'll still be here. Really. Pure water has pH 7.0; let it sit around and pretend it's Perrier, next thing you know, those water molecules are all over the carbon dioxide like a dog on a Dreamsicle, and the pH plunges to 5.6 with atmospheric concentrations of carbon dioxide (about 380 ppm or, under new Bush administration projections, 2,280 ppm by 2040). Higher concentrations of atmospheric carbon dioxide drops the pH even more, and heaven only knows what this means for the planet's coral reefs; the ocean has the bajeezus buffered out of it, but when you're talking about something that massive, anything goes. Maybe upping the temperature will throw the equilibrium in the opposite direction. :-P At least the "coral calcium" crap at the health food store will be cheaper. Try not to let too much too much strontium build up in your system. "Tums" are made with synthetic calcium carbonate; corals accumulate Sr, as well as lead and other heavy nasties at levels that you do not want to be ingesting. On the bright side, more CO2 = more caves, the very thought of which makes us troglodytes revel in ecstasy. But the really big caves are formed with sulfuric acid, which is probably biogeochemical in origin. That's another lecture. Bring a "blue book," there'll be a short quiz afterwards. Cheers, -AJHicks Chandler, AZ |
#10
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Languishing Paphiopedilum
Ok Aaron, the buffering ability of the bicarbonate ion is well known. The
solubility of CaCO3 decreases with increased temps above normal. This does not mean that the solubility increases with decreasing temps below ambient (look up buffers). In cooler temps, CaCO3 precipitates since the solubility coefficient is so low. The major factor here is the acidity which negates LeChatelier and the above discussion since CO2 is no longer one of the major players. Acetates, humic acids, chlorides, and nitrates of calcium are soluble and plentiful in peat moss mixes which overwhelms the buffering capacity of the bicarbonate ion, which was the point. I am a high school chemistry teacher of 34 years and put the 50's in my pocket, thank you. But as any other high school teacher knows, they leak back into the classroom anyway. Gary "Aaron Hicks" wrote in message ... "Gareth Wills" spaketh thusly: Sorry to disagree, in part, Steve,but Fowlie is wrong. The only chemicals (barring a few weirdos) that dissolve better in cooler temps than warm ones are gases such as oxygen. Calcium compounds are notoriously insoluble except in acids. Then, unfortunately for your system, you are going to have to lump calcium carbonate in with the "few weirdos" as its solubility decreases as temperature increases. I base my claims as regards to this paradox on statements made in two separate copies of the CRC Handbook of Physics and Chemistry, my attending graduate school in stable isotope geochemistry (even if I wasn't all there at the time), and perhaps most importantly, the laws of physics and chemistry. Poor, neglected calcium carbonate, every caver's best friend. The solubility of calcium carbonate is tied to the concentration of the bicarbonate anion, which is present in solution in low concentrations thanks to atmospheric carbon dioxide. An increase in the temperature causes carbon dioxide to become less soluble in solution and, along with it, the solubility of calcium carbonate also decreases. You may thank LeChatelier's Principle for this (although, if you wish to thank me instead, 20's and 50's are welcome- send them to your local high school chemistry teacher). An excellent primer, if you're bored to death, is found he http://members.aol.com/profchm/comonion.html Back to carbonate solubility! Behold! The caver's formula: CO2 + H20 -- H2CO3 Carbon dioxide plus water gives you carbonic acid. Carbonic acid loses its first proton- a moment we should all pause to reflect upon, but not he privately. When you're done, come back; we'll still be here. Really. Pure water has pH 7.0; let it sit around and pretend it's Perrier, next thing you know, those water molecules are all over the carbon dioxide like a dog on a Dreamsicle, and the pH plunges to 5.6 with atmospheric concentrations of carbon dioxide (about 380 ppm or, under new Bush administration projections, 2,280 ppm by 2040). Higher concentrations of atmospheric carbon dioxide drops the pH even more, and heaven only knows what this means for the planet's coral reefs; the ocean has the bajeezus buffered out of it, but when you're talking about something that massive, anything goes. Maybe upping the temperature will throw the equilibrium in the opposite direction. :-P At least the "coral calcium" crap at the health food store will be cheaper. Try not to let too much too much strontium build up in your system. "Tums" are made with synthetic calcium carbonate; corals accumulate Sr, as well as lead and other heavy nasties at levels that you do not want to be ingesting. On the bright side, more CO2 = more caves, the very thought of which makes us troglodytes revel in ecstasy. But the really big caves are formed with sulfuric acid, which is probably biogeochemical in origin. That's another lecture. Bring a "blue book," there'll be a short quiz afterwards. Cheers, -AJHicks Chandler, AZ |
#11
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Languishing Paphiopedilum
The skies did open, and through the rent the mighty voice of "Gareth Wills" spaketh thusly: Ok Aaron, the buffering ability of the bicarbonate ion is well known. The solubility of CaCO3 decreases with increased temps above normal. This does not mean that the solubility increases with decreasing temps below ambient (look up buffers). Check your CRC. The solubility of calcium carbonate INCREASES dramatically below ambient. In the event you have misplaced it, I refer you to a chart from Faure's "Principles and Applications of Inorganic Geochemistry," page 223, posted for your viewing pleasure at: http://members.cox.net/ahicks51/calciumcarbonate.jpg Two partial pressures of carbon dioxide are given; the upper curve is closest to actual. As can be seen, the solubility of calcium carbonate (as measured by the [Ca+2], coming from dissolved calcite) increases dramatically as temperature drops, particularly *below* 20 C. Solubility does, in fact, increase with decreasing temperature. "The solubility of calcite [calcium carbonate, limestone] is also affected by the temperature because of changes in the numerical values of all the equilibrium constants. Garrels and Christ (1965) compiled the set of values of the relevant equilibrium constants between 0 and 50 degrees C that is listed in Table 12.6 [not shown here]. We see by inspection that the dissociation constants of carbonic acid _increase_ with increasing temperature, whereas the solubility product constants of calcite and CO2 _decrease_. As a result, the solubility of calcite in pure water in equilibrium with CO2 of the atmosphere actually _decreases_ with increasing temperature, as shown in Figure 12.4 [as above]. For example, a saturated solution of calcite in equilibrium with CO2 at 3x10^-3 atm contains about 75 mg/L of Ca+2, at 5 degrees C but only 40 mg/L at 30 degrees C." _Emphasis_ is that of the author. [This stuff] is mine, as are typos. In cooler temps, CaCO3 precipitates since the solubility coefficient is so low. No. This is why hot water heaters fill with calcium carbonate precipitate in regions with hard water. Cold water in, hard water out, leave the calcium carbonate behind. Wait five years until it's full of "sand." The major factor here is the acidity which negates LeChatelier and the above discussion since CO2 is no longer one of the major players. Acetates, humic acids, chlorides, and nitrates of calcium are soluble and plentiful in peat moss mixes which overwhelms the buffering capacity of the bicarbonate ion, which was the point. Ah! A correct statement. I do not dispute this. However, stating that Fowlie is wrong because the solubility of calcium carbonate is proportional to temperature is wrong, and I will take issue with this. I will happily admit that the other components of the system, when in sufficiently high concentrations, will quickly overwhelm the system (but not "negate" LeChatelier- one does not negate laws of chemistry and physics without congressional approval, or at least help from the president of the American Chemical Association). One last factor of potential interest is the ability of roots to remove carbon dioxide from their environment, fostering the precipitation of calcium carbonate and other minerals within proximity of their roots. When fossilized, they form "rhizocretions." Do a Google search. They're cool. These trace fossils may also occur after plant death, so they're not an absolute indication of this sort of activity on the part of the plant. -AJHicks Chandler, AZ |
#12
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Languishing Paphiopedilum
OK, AH, you did your homework. Thanks for the corrections to my incomplete
and impulsive response. I spoke too quickly in generalities when I was meaning to apply it to the situation of acid soil and paphs and not systems where the pH is neutral or above or within the effective buffering range of bicarbonate. Acid solutions are not covered in your arguements. My references are not here with me, but I believe a warm acid will dissolve carbonates better than a cold one. So my terms of "wrong" and "negate" were inappropriate. "Not fully applicable to the situation" would have been better. Let's both stick to chemistry applicable to this board and its purpose - to grow better orchids. Gary "Aaron Hicks" wrote in message ... The skies did open, and through the rent the mighty voice of "Gareth Wills" spaketh thusly: Ok Aaron, the buffering ability of the bicarbonate ion is well known. The solubility of CaCO3 decreases with increased temps above normal. This does not mean that the solubility increases with decreasing temps below ambient (look up buffers). Check your CRC. The solubility of calcium carbonate INCREASES dramatically below ambient. In the event you have misplaced it, I refer you to a chart from Faure's "Principles and Applications of Inorganic Geochemistry," page 223, posted for your viewing pleasure at: http://members.cox.net/ahicks51/calciumcarbonate.jpg Two partial pressures of carbon dioxide are given; the upper curve is closest to actual. As can be seen, the solubility of calcium carbonate (as measured by the [Ca+2], coming from dissolved calcite) increases dramatically as temperature drops, particularly *below* 20 C. Solubility does, in fact, increase with decreasing temperature. "The solubility of calcite [calcium carbonate, limestone] is also affected by the temperature because of changes in the numerical values of all the equilibrium constants. Garrels and Christ (1965) compiled the set of values of the relevant equilibrium constants between 0 and 50 degrees C that is listed in Table 12.6 [not shown here]. We see by inspection that the dissociation constants of carbonic acid _increase_ with increasing temperature, whereas the solubility product constants of calcite and CO2 _decrease_. As a result, the solubility of calcite in pure water in equilibrium with CO2 of the atmosphere actually _decreases_ with increasing temperature, as shown in Figure 12.4 [as above]. For example, a saturated solution of calcite in equilibrium with CO2 at 3x10^-3 atm contains about 75 mg/L of Ca+2, at 5 degrees C but only 40 mg/L at 30 degrees C." _Emphasis_ is that of the author. [This stuff] is mine, as are typos. In cooler temps, CaCO3 precipitates since the solubility coefficient is so low. No. This is why hot water heaters fill with calcium carbonate precipitate in regions with hard water. Cold water in, hard water out, leave the calcium carbonate behind. Wait five years until it's full of "sand." The major factor here is the acidity which negates LeChatelier and the above discussion since CO2 is no longer one of the major players. Acetates, humic acids, chlorides, and nitrates of calcium are soluble and plentiful in peat moss mixes which overwhelms the buffering capacity of the bicarbonate ion, which was the point. Ah! A correct statement. I do not dispute this. However, stating that Fowlie is wrong because the solubility of calcium carbonate is proportional to temperature is wrong, and I will take issue with this. I will happily admit that the other components of the system, when in sufficiently high concentrations, will quickly overwhelm the system (but not "negate" LeChatelier- one does not negate laws of chemistry and physics without congressional approval, or at least help from the president of the American Chemical Association). One last factor of potential interest is the ability of roots to remove carbon dioxide from their environment, fostering the precipitation of calcium carbonate and other minerals within proximity of their roots. When fossilized, they form "rhizocretions." Do a Google search. They're cool. These trace fossils may also occur after plant death, so they're not an absolute indication of this sort of activity on the part of the plant. -AJHicks Chandler, AZ |
#13
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Languishing Paphiopedilum
I got around to actually repotting it yesterday. The roots were very
good and they had dozens of nice growing white tips. As for the leaf span you asked for. The plant was once over a 12-inch leaf span, now it is 6 inches! I put marble in the bottom of the pot. If it wants calcium I guess it can towards the rocks. Right? It is odd I know! I am going to take it to the Paph forum in DC later this month. Someone there will likely see immediately what is wrong. Thanks Jim PS I also repotted a Paph Susan Booth x bellatulum, kind of similar breeding, it was pot bound in the same mix Transcolor, it grew next to Transcolor, and was last repotted with Transcolor, but it looks great unlike Transcolor. "Gene Schurg" wrote in message link.net... Germ, Interesting problem! You say that the roots are healthy and growing which is the first suspect in a mystery such as this. 5 inch pot sounds a bit large but you didn't state the leaf spread so I can't say for sure. But since the roots are growing well I assume this is not the issue. You mention the larger leaves are dropping and new smaller ones are replacing them. I see this when a plant gets too much light and is stressed. Doesn't sound like light is your issue since you moved the plant under lights and before that it was in an east window. Hmmmm (could it be the butler in the library with the candlestick?) What a mystery....maybe it's the potting mix? no, you said you are using it for other paphs. Maybe the plant needs something you're not giving it? Is this one of the paphs that need calcium in the mix? If this is the case the change of mix would explain why it grew for a while and then started to fail. Check the plant's parentage and see if it has calcelious (I can't spell) .....parents that need calcium in their mix to enable them to take up nutrients. Let us know what you find out. Good Growing, Gene |
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