Looking for secret

[Ozpaph]

Thank-you all for enlightening me.

 

[Rick]

Yes, Wayne asked me for a pic of my zieck few weeks ago for comparison of his compot. I think it might be real zieck.

OK, I found out that HS1451 is definitely on the Hung Sheng price list. But also separate from any of the ziekianum's listed.

HS has pics of the ziekianum "bear" flowers, but no pictures showing for any papuanum.

I emailed them so maybe something will come up.

I am also encouraged that the pics of parnatatum on his site look like the authentic species (since I got a few of those too).

 

[dodidoki]

OK, I will buy TDS meter. Optimal ppm value for paphs?

 

[Rick]

OK, I will buy TDS meter. Optimal ppm value for paphs?

I don't think there is a universal optimal value, especially if you consider that different ions effect the conductivity differently.

So I just try to keep it much lower than my well water. Maybe try to shoot for way under 300 useimens/cm. The mastersianum are consistently below 200 us/cm. May need to check units on whatever you get.

I actually got a conductivity meter instead of TDS (total dissolved solids). Also the unit I got (Hanna 98331) has a soil probe that's real handy for working with pots/baskets.

 

[dodidoki]

Thanks. Does EC mean electrical conductivity? I ordered EC/ TDS meter.

 

[gonewild]

Thanks. Does EC mean electrical conductivity? I ordered EC/ TDS meter.

Yes it does.

 

[Stone]

Its worth noting too that different fertilizers supplying the same amount of a nutrient element can have different EC values.
(Sorry Rick I just noticed you did note that)

For example 100ppm of N from Calcium nitrate has an EC of 0.84 dS/m (840 uS/cm)
100ppm of N from Ammonium nitrate has an EC of 0.51 dS/m
100ppm of N from Ammonium sulphate has an EC of 0.96 dS/m

So you need to have a some idea of the particular compound and its effects before you can make a lot of sense from an EC reading.

Example: if your fertilizer has Ammonium nitrate as its N component, the same EC could give you close to double the N as it would if you were using Cal nitrate.
If it has Urea, it WILL NOT register BUT plants will see it as any other salt. So you need to increase the measured EC by 1.5 dS/m (1.500 uS/cm) for every gram of Urea per Lt.

If your water has the slightest amount of NaCl, your plants could be on a starvation diet going by EC alone.


If you have pure water and you're happy with the fertilizer you use, then you're laughing

 

[Stone]

Maybe try to shoot for way under 300 useimens/cm. The mastersianum are consistently below 200 us/cm.

I'm begining to think 300 (or 0.3 dS/m) might be too low. (At least for summer) Thats been about the EC of my fert solutions with basically feed - flush - feed etc. That equates to under 30ppm N (for my fert.)

If I look at the Dutch figures for optimum EC and ppm-N for Chrysanthemum or Gerbera grown in rockwoll. ( and both of these are deemed VERY senstive to salinity ) They give an EC (Gerbera) of 1.5 dS/m (1500 us/cm) and 158ppm NO3 + 21ppm NH4. But thats for constant moisture levels.

But we dry Paphs out a bit so lets half the EC again. That brings it to 0.75 dS/m (750 us/cm) That would bring my N to aprox. 75ppm. Now if we assume that Paphs are even more sensitive (don't know for sure but unlikely) lets bring it down more to say 0.5 dS/m. I think to go down any more with N will slow growth. I have seen a slightly improved response going from 0.3 to 0.5 or 0.6
Of course now its mid summer here and everything is booming with all the light and heat. Bringing your EC down to 0.2 or lower in winter would probably be wize.

 

[valenzino]

All those species (appart from P.wenthworthianum,due to lack of plants for reproduction), have been succesfully reproduced.(including Cyp irapeanum etc)...And mostly all times they die due to wrong media/conditions...but some are really a challange...
In my opinion the problem linked to the dependency of the plant to the fungi,have to be seen under a different point of view,the michorizae protect the plants from other phatogens.So,when the protection is lost,those plants becames very sensitive to various infections.This can explain also why are difficult to deflask...cause they have a poor immunitary system.Can also someway explain why are also sensitive to systemical chemicals...
Maybe can be interesting try to grow them with standard horticoltural michorizae that protects against various pathogens...

I opened this thread and discussion because of some problematic species, selenipediums, paph. wentworthianum, bougainvilleanum.
All of reports said that these plants died within a short time after digging out of their natural habitat. Other interesting point that arteficial reproduction of these species is impossible with our current knowledge.
I think, that these plants have chlorophyll for photosyntesis, indeed, however they are not independent from fungi, they got "something" from fungi what is essential to survive ( hormones maybe???)
Only one sel. aequinoctiale reported to bloom in GH, died soon after blooming. One palmifolium reported has bloomed in GH- only this one, what was digged out with a large soil ball. This one died after blooming, too.
I think bad fate of these plants begins with soaking their roots and desinfection against diseases with fungicides.
My first seleni arrived with bare roots, died within few weeks.
Second one has a little soil ball around roots, this one produced a nem growth, 80 cm tall, survived more than one year but nowadays is about to die. I think my efforts against rot killed its fungi.
If I will try again I think I will avoid seleni from any chemicals and will ask seller sending plant with bigger original soil ball.

 

[Ozpaph]

How do you test the tds/ppm of the mix without a soil probe?
Do you sit the pot in distilled water for a while then take the measurements?

 

[eggshells]

How do you test the tds/ppm of the mix without a soil probe?
Do you sit the pot in distilled water for a while then take the measurements?

If you are using a bark based mix. I dont think that a soil probe will work properly. It is best to run close to 0 ppm water through the pot and catch it in a basin. And then measure that.

 

[terryros]

The method published by several authors is to water/feed a plant and then an hour or so later, pour about 50 ml RO water through the plant sitting in a saucer. The amount can vary a bit with the plant size, but you need enough effluent to come through to do the measurement. Pour the effluent from the saucer into a container and measure the ppm/EC.

As noted by other authors, TDS meters that produce a ppm reading are actually measuring EC and then converting to ppm. However, different meters can use different conversion factors. I purchased a calibration solution at a hydroponics store and found that my meter has EC = 2 X PPM as the conversion (using the mostly commonly used units being used by Stone and Rick in this chain).

For example, when I make a fertilizer solution with K-Lite in my RO water at a calculated 50 ppm N strength, I get a measured ppm of about 250 so the EC is about 0.5. When I do the pour through method on most plants, my effluent is usually around the same as my fertilizer solution, so about 0.5 and I begin to flush if it starts to get much higher than this (I grow in sphagnum moss).

Thus, to get to the levels that Rick is talking about I would need to be using much lower concentration of K-Lite than 50 ppm N.


Sent from my iPad using Tapatalk HD.

 

[Rick]

How do you test the tds/ppm of the mix without a soil probe?
Do you sit the pot in distilled water for a while then take the measurements?

The standard practice is to slowly pour some water through the pot and collect/test and then mutliply by two.

Paph mixes are very open, so I find that water travels through the pot so fast that it does not pull much salt out. So I think something like you are suggesting is just as legitimate as long as you standardize the process for yourself.

You want to minimize the dilution effect of the water being added. If you have a cup or other water holding container that is very close in size to the pot in question, then use that. Fill up the pot, let it sit for maybe up to an hour, drip out and test.

You could collect a time series (15 min, 30, 60, 90...) to see when you get max transfer. Just take good notes so you can repeat with other pots to get consensus on your method.

 

[Rick]

The method published by several authors is to water/feed a plant and then an hour or so later, pour about 50 ml RO water through the plant sitting in a saucer. The amount can vary a bit with the plant size, but you need enough effluent to come through to do the measurement. Pour the effluent from the saucer into a container and measure the ppm/EC.

As noted by other authors, TDS meters that produce a ppm reading are actually measuring EC and then converting to ppm. However, different meters can use different conversion factors. I purchased a calibration solution at a hydroponics store and found that my meter has EC = 2 X PPM as the conversion (using the mostly commonly used units being used by Stone and Rick in this chain).

For example, when I make a fertilizer solution with K-Lite in my RO water at a calculated 50 ppm N strength, I get a measured ppm of about 250 so the EC is about 0.5. When I do the pour through method on most plants, my effluent is usually around the same as my fertilizer solution, so about 0.5 and I begin to flush if it starts to get much higher than this (I grow in sphagnum moss).

Thus, to get to the levels that Rick is talking about I would need to be using much lower concentration of K-Lite than 50 ppm N.


Sent from my iPad using Tapatalk HD.

Yes 0.5X EC = TDS is a calibration for sodium or potassium chloride. As Stone noted, the EC of individual constituents is all over the board, and you are generally looking at an average of constituent EC's. In tap water (generally low in Na/K salts but high in Ca/Mg salts, the conversion is usually closer to TDSX1.8 = EC.

The use of TDS/EC is really to track accumulations of salts in the mix, rather than target absolute values. As you noted, the EC of fert mix is pretty high compared to rain water or dilute tap water. So rather than looking at the EC of fertilizer influenced mix, you need to use potting mix with clean irrigation water as your baseline. Then you will get to see numbers in the lower range that I use as my target.

If you see numbers in the 200+ TDS (400 EC) range after a pot flush and you haven't applied fert in a week, then typically your potting mix is holding a lot of left over food from the previous feedings.

If you compare this to aquarium management, this is comparable to adjusting the feeding rate of your fish so you don't have piles of rotting uneaten food sitting in the bottom of the tank.

 

[Rick]

I'm begining to think 300 (or 0.3 dS/m) might be too low. (At least for summer) Thats been about the EC of my fert solutions with basically feed - flush - feed etc. That equates to under 30ppm N (for my fert.)

.

The point is not to get your plants used to sitting constantly in a salty mix comparable to your fertilizer, but to track how much salt is accumulating in your mix from feeding.

We've gone around on this a lot already, and noted that orchids (especially epiphytes) live in low EC environments (like less than 100) so if you see 200-300-400.... in your mix after a freshwater flush, then you have accumulated a bunch of leftover salt in your mix from overfeeding.

 

[Rick]

I'm begining to think 300 (or 0.3 dS/m) might be too low. (At least for summer) Thats been about the EC of my fert solutions with basically feed - flush - feed etc. That equates to under 30ppm N (for my fert.)

What is the EC around the roots of your awesome mounted plants?

Should be 0 in air. So we don't need to subject our potted plants to 300+ on a 24/7 basis.

 

[Rick]

If I look at the Dutch figures for optimum EC and ppm-N for Chrysanthemum or Gerbera grown in rockwoll. ( and both of these are deemed VERY senstive to salinity ) They give an EC (Gerbera) of 1.5 dS/m (1500 us/cm) and 158ppm NO3 + 21ppm NH4. But thats for constant moisture levels.

How can 1500us/cm be considered salt sensitive? That's almost 3X the conductivity of my well water, which is 2X the conductivity of the surface water for Nashville.

But once again if we treat our orchids as if they were annual cut flowers, I don't know how much more we can expect out of them past a year.

There was a fragment of insitu orchid data we can use. The kovachii field data. Soil EC was 400 us/cm. Water EC was 40 us/cm (I believe it said 20ppm). Now going back to the soil EC relative to fert EC this should have nothing to do with NPK fertilizer concentrations, but rather Ca/Mg salts. Maybe even some Na.

So if your salt source is strictly fertilizer and your fertilizer has a high potassium content, then your final pot EC after long term fertilizer impact will reflect a high concentration of built up potassium salts that are a lot more toxic to your plant than the predominant calcium salts in the insitu kovachii soil at an EC of 400.

 

[Stone]

How can 1500us/cm be considered salt sensitive?

Ok so I just went out and checked the EC of the insignes I have outside in the shadehouse. they are sitting premanently in about 2-3 cm of water and fed organic fert exclusively. They only ever did just ok in the glasshouse with the usual techniques. This year they are sending out prodigious amounts of new shoots and leaves and it wouldn't be too much to say they ware doing 3 times as well as previous years. The EC of the water ranged from 0.9 to 1.3 Thats 1300 us/cm with nice white root tips sitting in the water.
So there is obviously still more to learn. I plan to grow them this way permanently so time will tell.. But I beleive it has something to do with constant water. If you consider a normal paph sitting in bark and fed at say 0.5 (500 us), just after feeding you will have your 0.5, a couple days later you may have half of the water gone= media water EC 1.0 dS/m 1000 us/cm a few days later 3/4 of the water evaporated= media water EC 1.5 (1500 us/cm)= time to water! OR if you want to keep dry, reduce fert EC accordingly.

 

[Stone]

There was a fragment of insitu orchid data we can use. The kovachii field data. Soil EC was 400 us/cm. Water EC was 40 us/cm (I believe it said 20ppm).

The EC mesured in the soil came from the WATER in the soil. Thats where the nutrients were. Nothing would grow with 20ppm salts. Certainly not a big leafy plant. But 400 us/cm sounds about right. In fact higher than my EC lately!

 

[Rick]

The EC mesured in the soil came from the WATER in the soil. Thats where the nutrients were. Nothing would grow with 20ppm salts. Certainly not a big leafy plant. But 400 us/cm sounds about right. In fact higher than my EC lately!

Isn't all EC based on conductance of an aqueous solution? Still not sure what water was referred to with the conductance of 40. Maybe the through put water trickling over the soil.

Still lots of epiphytic plants get huge with no more than 20ppm of salts coming there way in the rain water.

And 400 us/cm is a lot less than 1500 and alot closer to 200-300