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David, I think the point is that potassium can build up to levels that can be damaging, not that applying it regularly at "traditional" levels will, by itself, be harmful.

There a lot of dynamics in the pot - flushing, drying, different absorption characteristics, repotting, application rates, substrate properties, etc. Some may be less sensitive to the buildup issues than others, and that's ignoring the particular plant.

I cannot tell you how many times I've seen folks grow plants great, and then "poof", out of the blue it just goes downhill. Is that due to K accumulation? I certainly cannot say for sure, but the transference of my knowledge of materials science to this arena makes it appear to be plausible, which is why we're experimenting.
 
DavidCampen said:
You are talking like its only since klite that people have been able to keep orchids alive. That is not correct..
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Agreed. That is a total over dramatization of what we've been seeing over the years.

However, if you pay attention to the complaints that come up on this site, and at your local orchid society, you hear pretty much the same problems that have plagued the hobby for decades (if not a full century).

We still have debates about "what is the natural life span of orchids" because no one (except the little old German lady in TN who NEVER fertilizes) can get XYZ plant to last more than 5 years. Or seedlings of XYZ are "impossible to raise to blooming size" (subsequently dependent on jungle collected plants (that die in 5 years!) and plants of XYZ stay short and stumpy in the GH, while in the jungle they are bigger than a house, or species XYZ is prone to disease #9 unless you dance naked in your GH during every full moon.:eek:

Allot of orchid culture is really dumbed down to a pretty low level of performance expectations. It's actually had very little science applied to it, and mostly hobbiest anecdote. I can say that as a UC Irvine trained reseach scientist.

Now most of my collection is Slippers (Paph, Phrag, and Mexi), Bulbos, and Phalaenopsis species, but I have a handfull of laeliinae (and even a Catesetum species). Universally adult plants are doing better/bigger/healthier since the last 2 years of low K compared to the previous 8 years of MSU. The rate of seedling loss is a fraction of what it was in previous years, and seedlings are growing at an unparalleled rate. Check out Bjorns thread on his seedlings too using K lite.

I've already run the gambit of light/temp/humidity mods, so nutrition is the last frontier and the present direction is really panning out.

So why should I go back to the old ways?
 
Ray said:
I think the point is that potassium can build up to levels that can be damaging, not that applying it regularly at "traditional" levels will, by itself, be harmful.
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????

I think this one is already out of the barn Ray. K lite was developed to address a littany of orchid growing performance complaints. Not just a fun chemistry experiment.
 
cnycharles said:
;) it depends on where you get your water from; some places the water is pretty stinky, so 'just a little dab 'll doya'
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Charles if you can smell it (rotten eggs) that's hydrogen sulfide. But sulfate doesn't smell.

My well water last measured has 270 ppm of sulfate (and smells just fine actually), so I can add 5% (a virtual spit) of my well water to RO and have more than enough sulfate to make any orchid happy.

Our Nashville tap water is pretty average for the US with hardness between 80-100 and has sulfate somewhere around 50 or so ppm.

10-20% (I guess that's up to 4 spits!) in RO would accomplish the same thing.

Most of us fertilize once a week, but water a few more times in between for flushing. I think its a great idea to understand your local water, and use it in dilute quantities to get things like sulfate, chloride, bicarbonate, calcium , magnesium, maybe even some silicates....... Without a huge pile of N in the deal.
 
DavidCampen said:
QUOTE] Perhaps cypripediodeae have some special needs but with laeliinae and catasetinae and various other genera that I grow I don't see what the problems are that would be cured by klite. And really, I don't see why potassium should be so toxic to cypripediodea, the half dozen that I have seem not to have been harmed by the more conventional K ratios
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.

This is what I'm talk'n about::clap::rollhappy: BTW David, I also agree that S should be about 10-12% of N. (with pure water)
 
Here's a mathematical perspective.

I took and average mature green leaf from my Catt. mossiae and Prosthecia cochleata.

Both leaves were similar in dimension 7"X 1.75" (Cm) and 8" X 1.5" (Pc)

The wet weights of each was 8.11g (Cm) and 2.60g (Pc)
Dry weights came out to 0.968g (Cm) and 0.54g (Pc)

The Zotz leaf tissue concentrion for a mature leaf (average for all orchids tested that are not ant associates) is 9.7 mg/g dry weight.

So that means that if the K for these two species is comparable to a host of jungle Panamanian orchids, they would have a total of 9.4mg and 5.2mg of K per leaf.

So for the plant to create these leaves from Klite (over the coarse of a 6-8 month growing cycle) you would need to appy about one or two liters of K lite at 50ppm N, but only about 175 ml (over 6-8 months) of regular MSU.

With weekly feeding thats 32 feedings over 8 months. So the equivalent amounts of solution per feeding are:
5.4ml/feeding of MSU versus ~50 mL/feeding of Klite.

For K sensitive species, which is easier to overdose? Since mounted plants don't retain fluid past the feeding, you could see that mounted plants have an advantage over potted for reducing the chance of overfeeding. Once you can picture how much K is need for a full size Catt leaf, how does that compare to an out of flask seedling?
From a test variability study, with water running out of pots at different times/rates...... how can you know what the real dose is per plant (except in SH or full hydro conditions? Some days you feed superficially some days you pour it on. Some weeks you skip, some weeks you lower the concentration. Some folks do the whole "winter rest" thing and don't even feed for months on end.

Now I will say that the Catt mossia is doing just fine after a couple of years under this regime, its added a few new growths, and its not eating up old back bulbs or leaves. The Prosthecia on the other hand has gone nuts over the last 2 years. Leaves, bulbs, 20-30% bigger than pre low K and blooms for months on end (I have 4 spikes going this year). Before low K I would have been totally satisfied with the way the Prosthecia was growing with MSU. I wouldn't have considered it a "problem plant". This is a commonly grown species so lots of good experienced growers in our society were very impressed with the quality of what this plant is doing compared to their results. So it was a total bonus as far as I'm concerned, and if you are satasfied with your plants then be happy.

There is a range of K that was found in Panamanian orchids. Maybe the Prosthecia is more like Epidendrum nocturnum that only had 2.3 mg/g of K in its leaves? At that rate a couple tablespoons per week of Klite is more than enough.
 
Relative amounts is important. What was the amount of N in the same leaf tissue? If you include that you should find that with Klite you are overfeeding with N to get the required amount of K.

With weekly feeding thats 32 feedings over 8 months. So the equivalent amounts of solution per feeding are:
5.4ml/feeding of MSU versus ~50 mL/feeding of Klite.
Click to expand...
If you want someone to actually be able to follow your argument then you should give ppm of each major element in the 2 solutions. I could do it with a bunch of backtrack calculations but it would have been easier for you to have done this as part of your calculations.

To repeat myself, it seems to me that relative amounts are important and in that regard, Klite (actually KPlite) is unbalanced in the amount of K and P (not to mention that sulfate is not even given in the analysis).
 
DavidCampen said:
To repeat myself, it seems to me that relative amounts are important and in that regard, Klite (actually KPlite) is unbalanced in the amount of K and P (not to mention that sulfate is not even given in the analysis).
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Actually it is not unbalanced. The point of K-lite is that the "balance" has been redesigned. K-lite assumes a new ratio between the elements. You can believe that the old ratio was correct for all the elements but the new ratio so far is proving to be an improvement. If this improvement holds up then we have a new standard for the correct NPK ratio at least for general orchid species.
 
gonewild said:
Actually it is not unbalanced. The point of K-lite is that the "balance" has been redesigned. K-lite assumes a new ratio between the elements. You can believe that the old ratio was correct for all the elements but the new ratio so far is proving to be an improvement. If this improvement holds up then we have a new standard for the correct NPK ratio at least for general orchid species.
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By tissue analysis, which is what Rick was just doing, it _is_ unbalanced.

Maybe it is superior based on results but by comparing the ratios of elements in plant tissue it is unbalanced.

The point of K-lite is that the "balance" has been redesigned.
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That is a "words mean whatever I say they mean" type of statement - Klite is balanced (a redesigned balance) because you say it is balanced. Sounds like marketing speak, especially the part about "redesigned balance".
 
I think that the reality is that:

1) Tissue analysis tells you what is in the tissue, not what the plant needs to operate optimally.

2) Nobody knows what the optimal nutritional levels are.

3) Those "optimal levels" are likely different among species, if not among individuals of the same species.

Therefore, we can experiment, adjusting the relative amounts and dosing levels, and become good observers.
 
DavidCampen said:
By tissue analysis, which is what Rick was just doing, it _is_ unbalanced.

Maybe it is superior based on results but by comparing the ratios of elements in plant tissue it is unbalanced.
Click to expand...

The ratios of elements within plant tissue are not going to be the same as the ratio of the elements in the environment. The only thing you can read from a leaf tissue analysis is if it's elements are out of balance compared to a previous sample from the same plants or from the known average of the test block. You can make assumptions compared to average values known within a species but every different location will have different values.. You might want to rethink how you perceive "balance", ratios of fertilizer will never be in equal balance to the ratios of the same elements in plant tissue.

That is a "words mean whatever I say they mean" type of statement - Klite is balanced (a redesigned balance) because you say it is balanced. Sounds like marketing speak, especially the part about "redesigned balance".
Click to expand...

It would make good marketing speak since it is an accurate statement. It is balanced in that the newly defined ratios are yielding better plant growth and health than the "old" assumed balanced ratio. Balance simply means that they are in the best ratio to provide the best plant health.

Marketing has nothing to do with the discussion or trials of K-lite here on ST.
When you make a statement like that you imply that I am exaggerating the values of the K-lite balance to sell it. I have NO connection to chemical sales.
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I think this is just semantics.

If you think of "balanced"as being "of equal weight", as in the use of a laboratory balance, then a "balanced fertilizer" would be something like a 20-20-20.

If, on the other hand, you are using the word as an expression of "correct combination of nutrients", as in a "balanced diet", then the term COULD apply to any formula - assuming we know what the correct combination is.
 
gonewild said:
Marketing has nothing to do with the discussion or trials of K-lite here on ST.
When you make a statement like that you imply that I am exaggerating the values of the K-lite balance to sell it. I have NO connection to chemical sales.
Click to expand...

Sorry, it was an attempt at amusing hyperbole but it went beyond that to being incendiary; I apologize.

Ray said:
I think this is just semantics.

If you think of "balanced"as being "of equal weight", as in the use of a laboratory balance, then a "balanced fertilizer" would be something like a 20-20-20.

If, on the other hand, you are using the word as an expression of "correct combination of nutrients", as in a "balanced diet", then the term COULD apply to any formula - assuming we know what the correct combination is.
Click to expand...
Yes, that is a precise recapitulation.
 
Ray said:
I think that the reality is that:

1) Tissue analysis tells you what is in the tissue, not what the plant needs to operate optimally.

2) Nobody knows what the optimal nutritional levels are.

3) Those "optimal levels" are likely different among species, if not among individuals of the same species.

Therefore, we can experiment, adjusting the relative amounts and dosing levels, and become good observers.
Click to expand...

I think this goes back to the definition of what is "optimal". "Beauty is in the eye of the beholder" they say.

Optimal for a top fuel dragster is totally different than optimal for a indy race car (even though they are both cars).

COMPARING tissue level concentrations of nutrients in wild vs cultivated plants is a pretty good exercise for defining "optimal". It's obvious when you see the data that there is a difference between wild and cultivated plants (particularly in regard to K,Ca, Mg content and ratio).

It's also apparent that wild plants seem to do better in the wild than in culture. Last longer, bloom great, without all the effort of repotting, pesticide, fungicide......

Now if you couple the above 2 exercises (comparison of tissue sample data, and defining performance objectives by comparing wild orchid performance with cultured orchid performance) with the fragments of actual plant physiology and environmental data that we've pieced together on this project, I think you really can "know" what optimal levels are.

Now "optimal" is going to have a broad range, not a single number, because of all the variables concerned. Like individual species sensitivity, age/size of plant, potting conditions, and everything else that really factor into what toxicologists do to provide a single universal protective value for all species under all conditions.

There is a profound shift in philosophy in this exercise in the basic sense from "what is the least we can get away with to assure optimal performance versus what is the most we can get away with to assure optimal performance".
But I often see we frequently get stuck debating what is optimal for the sake of having something to debate.
 
Ray said:
I think that the reality is that:

1) Tissue analysis tells you what is in the tissue, not what the plant needs to operate optimally.

2) Nobody knows what the optimal nutritional levels are.

3) Those "optimal levels" are likely different among species, if not among individuals of the same species.

Therefore, we can experiment, adjusting the relative amounts and dosing levels, and become good observers.
Click to expand...

If we take as an assumption that the growth of jungle plants is "optimum" (probably never ending debate), then we "know" from data.

1) The amount (and ratios) of nutrients in the environment available to orchids IS different from what we typically supply in culture.
2) The amount (and ratios) of nutrients in leaf tissue is different between wild and cultured plants.
3) The uptake of nutrients is not strictly passive, but partially active AND selective, and the reason we see differences between wild and cultured leaf tissue concentrations.

Then I think we can say we are getting close to "knowing" what are optimal levels of nutrients, and move on to the questions of application.

This may completely fall apart for multigenerational man made cultivars with different performance objectives than wild species orchids, but I'm focused on species not hybrids. But at least in my gh with less than 2% of my total collection as complex hybrids I'm seeing good results with low K for them too.

I certainly have not seen "starvation"/ deficiency symptoms of anything.
 

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