Ok
I was looking into why plants may not effectively utilize nitrate.
The same ratio of nitrate to ammonical N in K lite is the same as for the old MSU (which seemingly supplied enough N in the past for some). The most significant exceptions seem to be when pH is run up, and buffering content (calcium carbonate and bicarbonate is high).
Apparently the nitrate reductase system (which depends on Fe and Mo to catalyze the reduction of nitrate) uses phosphate and/or sulfate. Both of which were reduced in K lite.
In particular phosphate is also bound up by calcium carbonate. Given the lime treatment used on Orchiata, and other buffering potential by high TDS waters and calcareous supplements, the likelihood of stalling out the nitrate reductase system in the plant is increased under low phosphate and sulfate availability.
Adding epsom salt will increase both Mg and SO4. If you can find some Mg-Phosphate could be even better. There's already more than enough Ca in this system, so I wouldn't go to bone meal. Iron phosphate (main ingredient in slug bait) could also be liberating.
Keep in mind that green in plants is due to presence of chlorophyll. It doesn't work (and make green) without Mg. A chlorophyll molecule is mostly carbon and hydrogen with 4 molecules of N and 1 of Mg.
Given that less than 1% of a plant is made up of NPK Ca Mg..... it doesn't take much to serve the plant. But we are doing lots of things with our chemical environment to impede the plants ability to take up these nutrients.
I can get my hands on magnesium phosphate (apparently it's used as a nutrient supplement for humans). Should I try this then instead of epsom salts?
Did they all have good roots when you got them?
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What caused the plants to loose roots? If the plants had good rots a yer ago and you fertilized them constantly with K-lite the roots were not lost due to a mineral deficiency.
You should suspect the old media as a possible cause for the problem.
Of the ones I know and remember, they had okay to decent root systems. The 'Oriental Red' x 'MM' had a good root system, the 'Jim Krull' x 'CC' didn't. The acclaimed roth 'MM' x self had a doable root system.
Why they lost roots? Probably a combination of the first two plants traveling here bare rooted from America, plus an inexperienced new Paph owner. I repotted all roths except 'Starship', since two of them were bare rooted, and the other one was from Popow, whom, I have experienced, usually over pot the Paphs.
I've never said that they've lost any roots due to mineral deficiency.
I don't see that the color in these two plants is much different. Consider that Mutant's picture color is off white balance towards too much yellow.
Most in-situ pictures are taken of the best specimens rather than sickly looking plants. And most orchids growing in the wild are growing in near ideal light levels and not fried under T5 lighting. If the wild plants were not in ideal light they probably would die off as seedlings.
No disagreement with this idea. But you can not trust making color evaluations from photos taken in different color light spectrums.
Mutant's photos color balance are not correct and they present the foliage more yellow than in reality.
Not reducing Potassium in the fertilizer. I'm suggesting that it had accumulated in the media and was available to the plants in excess. The plants tissue may have been already loaded with high levels of K when she got them.
Rather than looking at the leaf color to make the diagnosis I would look at the overall plant health and specifically root condition. Bright light combined with poor roots will produce plants like these.
Am I correct that her other plants are not showing the same symptoms?
I don't know how my picture looks like on your screen, but on mine, it's very close to how the colour appears IRL. This roth was much darker than the others when I got it, I think I might even have mentioned that it had such a dark green compared to the ones I had then. It has paled considerably, and stripes have started to appear on the lower leaves.
You can't say that it's an issue of colour balance in the photos, when I, the owner of said plants, say that they have paled and turned more yellow/brighter green compared to when I got them. The photos got me to realize that something was off, since they have lost the colour gradually and I hadn't realized how much paler they had gotten.
And if I compare my 'Oriental Red' x 'MM' to egshells sibling, mine is much much paler.
I don't say it's not a light issue, as I've said, I did keep the T5 too close to the plants, but I think there's more than that to it.
Some of my other plants are showing the same symptoms, some don't seem to care at all.
During the winter, many of them lost leaves, which I think I might have mentioned in some thread somewhere. And I thought it could be because I fed them too much fertilizer. Because of this, I flushed the pots for about a month, and the problem reduced. Now, many of them started to show the same signs, and I thought it could have to do with the media being too old, so I've repotted almost all of them (only two left). Some of the plants showing the symptoms, didn't have good root systems, some though did have good root systems, so it seems to depend on what species they are. My malipoense had terrific roots, but are also showing signs of this, whatever it is.
My Phals are also showing symptoms of some sort of lacking. I reacted that almost none of them started making any new leaves now during spring, so I started giving them some 5-5-5 fert, and they started producing leaves. They are not pale, but they don't show the same growth pattern they used to do. They, on the other hand, have massive root systems, and they flower. It's just the leaf production that seems to have decreased.
She also got the plants on different times and not all at the same time. Let's say if she doesnt correct this now. That particular plant of hers could became more paler as time goes by.
Regarding the T5. I dont think that a plant that grows under T5HO bulb gets a higher light intensity than a plant growing in a cliff exposed to the sun. I actually grow my plants particularly the multiflorals under 4 x 4' of T5HO bulbs.
I understand you concern about the color balance. However she stated herself that its actually a pale yellow. I think we should trust her judgement on that as she probably knows what color yellow is. And even her photo shows that the discrepancy regarding color balance isnt that much.
She have stated on other threads (My collection) that her paphs are pale at the moment and feeling depress. I am assuming most if not all her paphs are having this issue. Correct me if I'm wrong mutant.
Yes, the seedling roth I've had for the longest is 'Starship', the second is the acclaimed 'MM' x self.
I had my T5 too close to the plants, which was why my 'Jim Krull' x 'CC' got badly burnt. I didn't realize this until it got burnt, and someone pointed out that my MK also showed signs of too much light on the leaves closest to the T5. I raised the T5 about a month ago. But since the plants also have grown paler overall, this isn't the only issue I think.
Yes, please do.
They (the multis except the gardineri) are all paler than before.
Yes, some other show the same signs as these guys do, but I think the roths are the ones the most afflicted. But that could have to do with them needing more nutrition, right?
