From flasks to blooming plants, part 2: Moving forward.

I had to split my thread due to size limitations, so for those that have not seen Part 1, please jump to that one http://www.slippertalk.com/forum/showthread.php?t=29235
I started saying that 19 flasks are coming my way soon. Two of them are these two, the first being stonei album,

the other is micranthum album. Darn expensive and I do not like the yellowing, but I got a reduced price, the roots are good and its not seen often. If these are all surviving (5 of them) then the micranthum album may become cheaper than the tigrinum????

Thats it folks, hope you can have use of some of the information. I have omitted info about my fertilizing , partly because my ideas are relatively controversial and also because they are constantly evolving (hope to the better) But basically, feed with every drop and have it diluted to low levels like 200 ppm TDS (equals approx 40ppm N)

Good looking flask. Hopefully, these do well for you too!

I'm drooling on micranthum alba.

:drool::drool: Good luck on this! I wish you great success!

I wish I had them both. I hope you have good success.

ARRRRRRHHHH!!!!!!!!!!!



Er, um, cough cough, I mean good luck. :sob:

Looks like a nice order from Ching Hua! Those stonei album and micranthum album should do well.

Flasks from CH have always grown well for me. I hope they do well for you, congratulations on your purchase!

NYEric said:

ARRRRRRHHHH!!!!!!!!!!!



Er, um, cough cough, I mean good luck. :sob:

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So, you finally found the site Eric? Sorry about the wrong link, its fixed now:rollhappy:

micranthum album I would love to have one,
But the prices I have seen at them are to high for me.

Hope you are doing well, and have maybe one day a flask to spare or some seed.

It's a baby factory Bjorn!!!

Crank them out!!!!

Have you been tracking pH or TDS in your potting mixes?

I just started a little bench experiment today with sphagnum moss and aragonite sand for buffer. It's only 3 hours in, but I'm pretty amazed as to how little aragonite it takes to buffer the moss.

But the aragonite is like a coarse sand (not chips), so a little may go a long way for fast pH control.

For preview I'm getting a pH of 5.8 with only 1 gram of sand added to about 50 ml of tightly compressed moss (saturated in RO water). On a weight to weight basis that may seem like a lot of aragonote, but on a volume basis you can do a lot with 50 ml of compressed moss. Also I went down from the 1 gram of sand, and even with only 0.2gr of sand, I'm getting a pH increase over the control. At the end of the test I'll measure alkalinity.

Another concern I posted about calcium carbonate solids is that they can adsorb a lot of phosphate. So you might want to check to see if P is coming up short in some of these systems where plants may be going slow.

Great thread! It is a work in progress for you! Very informative, thank you!

Rick said:

It's a baby factory Bjorn!!!

Crank them out!!!!

Have you been tracking pH or TDS in your potting mixes?

I just started a little bench experiment today with sphagnum moss and aragonite sand for buffer. It's only 3 hours in, but I'm pretty amazed as to how little aragonite it takes to buffer the moss.

But the aragonite is like a coarse sand (not chips), so a little may go a long way for fast pH control.

For preview I'm getting a pH of 5.8 with only 1 gram of sand added to about 50 ml of tightly compressed moss (saturated in RO water). On a weight to weight basis that may seem like a lot of aragonote, but on a volume basis you can do a lot with 50 ml of compressed moss. Also I went down from the 1 gram of sand, and even with only 0.2gr of sand, I'm getting a pH increase over the control. At the end of the test I'll measure alkalinity.

Another concern I posted about calcium carbonate solids is that they can adsorb a lot of phosphate. So you might want to check to see if P is coming up short in some of these systems where plants may be going slow.

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Thanks Rick, you do touch something I have been speculating on. Because even if I like to use marble chips, I am not always using it. Some species seem to like it, other not. You see it on their root growth. On the other hand, I do like the gravel due to the packing, or lack of, leaves a lot of air, does not degrade or accumulate salts (leca can), ease of potting due to its free flowing characteristics, imparts stability to the pot due to weight, etc.
Ok, that was my reasons for using marble chips. You are entirely right concerning the effect on pH, if you mix water at pH 5 with one chip, it does increase to approximately 7 at a surprising speed. Whether or not that is a problem is dependant on the species I believe. You are indicating that calcium carbonate can strip the fertiliser solution of phosphate producing highly insoluble calcium phosphate. This made me curious so I checked it up and found that the Ksp of Ca3(PO4)2 is indeed very low, in the ten in the power of -30 range, while aragonite has one of 6x10^-6 only. So based on this, one could believe that aragonite is much more soluble than calcium phosphate. That is not the case, both are soluble to a Ca level of some 100ppm if you do the calculation. It is not that straight forward though it all depends on the amount of calcium and pH in your feed. More about this in this paper:
http://www.jbc.org/content/143/3/703.full.pdf
If you are interested, you may repeat the following exercise with me:
If you use hard water with an alkalinity of 250mg/l and baCk mix 1:10 with RO water then you should have a Ca concentration in your irrigation water of approximately 0.625mmol/l . Using a Ksp for calciumphosphate of 2x10^-33 and a Ca concentration of 0.625 mmol/l yields a phosphate (PO4) solubility limit of approximately 1x10^-9 g/l (1 nanogram!!) expressed as calcium phosphate dissolved. So in other word, an effective way of stripping phosphorous is to use well water.oke:
That is probably not the case due to complex formation, pH influence etc.
Back to the limestone. It is definitely possible that limestone strips phosphorous. But so would any fertiliser mix with calcium. Based on that, it seems probable that the plants have mechanisms in which the uptake of P is regulated. In the following paper this is described to some extent.
http://www.plantstress.com/articles/min_deficiency_i/P uptake.pdf
The uptake seems to be via organic acids expelled by the roots, so it may definitely be possible that the plant can absorb precipitated phosphate.
Rick, you are right stating that marble chips influence the compost pH. And that not all orchids like it. So far my experience is that micranthum and vietnamense inparticular seems to like it, or at least tolerate it. Rothschildianum is more questionable, guess better to use more standard mixes.

Bjorn said:

It is not that straight forward though it all depends on the amount of calcium and pH in your feed.

Back to the limestone. It is definitely possible that limestone strips phosphorous. But so would any fertiliser mix with calcium. Based on that, it seems probable that the plants have mechanisms in which the uptake of P is regulated.

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As you mention, there is some complexity. The solubility of calcium-phosphorus compounds is pH dependent (which depends more on alkalinity, bicarbonate concentration, that calcium concentration. Also with the use of lime products, the distribution is not uniform throughout the potting mix. At the surface of the sand grain or chip, you have very high concentrations of calcium carbonate, but probably very low on the surface of the moss or bark particle.


So what happens during fertilzing? I would guess that 90% goes directly through the pot with the plants seeing just a few seconds worth of the full concentration. Especially since the total amount of root surface area in a pot is probably not that high compared to the rest of the stuff in the pot. Then a certain percent of water is held up in the organic materials. Some of this might also be in contact with roots, and most probably is not. This gives the plant a little more time to access the P. Then if the mix has a good mix of calcium carbonate structure in contact with the bark, then that could draw the P held in the bark/moss into the limestone sponge.

I expect the storage capacity of the limestone to be finite, and maybe bacterial/rhizosphere interactions can remove the P from the "sponge" effect. The effect will be based on the amount of calcareous material in the matrix.

Much of the reason I'm bringing this up is that many growers (myself included) felt I could adlib lime additions into pots without worry of consequences to nutrient uptake. So this exercise indicates that more is not better once again.

http://www.aoml.noaa.gov/flbay/millero1.html

Here's a more pragmatic project on the subject.

After stabilzing pH/alkalinity in the moss experiment I might try some pour though tests with weak phosphate solutions to see if there is any practical retention issues.

do you like challenges!? Good luck!

http://www.iasj.net/iasj?func=fulltext&aId=30168

Here's another complication with calcium carbonate adsorptions. Magnesium uptake.

At least this paper deals with real soils and plants.

Id give those micranhtums subdued light and regular mistings and weak, frequent fertilizing. They have outgrown their nutrient supply - that's why they are yellow (I believe)

Ozpaph said:

They have outgrown their nutrient supply - that's why they are yellow (I believe)

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Have they outgrown the supply, or has pot chemistry conditions made the available nutrients unavailable?

Larger/faster growing plants and similar size of other species just fine at the present levels, so I don't think anything actually needs more of anything, but refinement of conditions to get what is already there into the plant. That may actually need less of something competing with the material that is "lacking" in the plant.

Try to consider this like a car engine.

Its only able to handle so much gas per unit energy produced. The combustion process is based on having the correct air to fuel.

If the engine is small, adding more gas just floods the carborator and you end up with stalling. You can add more air, but is that motor really big enough to handle that much energy.

In other threads we've identitfied that wild orchids grow fine on much less than what we generally use. So I'd rather try what is in excess or figure out how to lean out an excess before just adding more fuel to the fire.

I brought up the use of calcareous materials in an earlier post and the complications (and benifits) they produce. But I have another data point in my lab trial that is pretty interesting.

It can be easier to understand if I could post the whole table. But at this point, the amount of alkalinity and TDS from aragonite sand I think is pretty amazing.

Compared to moss only pH = 4.5 and conductivity of 171, adding only 0.2grams of aragonite sand the pH is 6.31 after 2 days, with a conductivity of 414 us/cm. I have incremental additions of aragonite to 1.0 gram, (which is demonstrating a pH of 6.80 and conductivity of 667 uS).

0.2 gr (200 mg) in 100ml water = 2000ppm of aragonite, and by TDS the equivalent of ~120mg/L has dissolved to increase the pH and TDS of a straight moss system.

Now consider adding a full tsp of this stuff (or fine oyster shell) as a top dress to a 4" pot?