Phrag. Andean Tears weird discoloration

[treefrog]

For the last 5 months or so (I've had this plant for more than 2 years now), I've been observing weird discoloration of the top leaves of my Phrag kovachii x walisii. The leaves look healthy in morphology but the color is wrong.

All my other phrags have a nice healthy green coloration and they all receive the same care with regular fertilizer, iron and magnesium supplements. Also the roots of the plant are healthy
Does anyone has a hint on what is wrong?
Here are the pictures:

 

[Drorchid]

My first guess is that your pH in the pot is probably too low, at that stage you will see calcium deficiency. I think kovachii and its hybrids seem to be more sensitive to that, and prefer a higher pH (we grow ours in straight diatomite, which increases the pH in the media).

Robert

 

[Shiva]

Robert could very well be right but it's also possible that it's getting a little too much light. Some plants like a little more shade then the others. Also, looking at the medium in the pot, il may need repotting.

 

[Kavanaru]

I am with Robert onthis one. That decoloration looks more like nutrients deficiency than a response to excesive light....

 

[treefrog]

I was too under the impression it might need calcium. I normally water all my phrag with RO water with constant 50-100ppm of fertilizer. I'm switching it right back to tap water (mine has a lot of calcium).

 

[goldenrose]

What fertilizer are you using? Does it have calcium & trace minerals? Interesting, I can't see how one formula is going to fit the needs of all orchid plants.

 

[Eric Muehlbauer]

My kovachii x longifolium is very pale and streaky...I had added dolomite, and blamed it on that. I've repotted it into a new mix with no added dolomite...we'll see if it improves.

 

[Rick]

What fertilizer are you using? Does it have calcium & trace minerals? Interesting, I can't see how one formula is going to fit the needs of all orchid plants.

However if the pot pH is too high or low, then calcium (even when present) can become non available.

Iron tends to drop pH too, and also competes for phosphate.

It's interesting to see individual plants reacting this way (I'm sure Treefrog is more concerned than "interested") so we'll see if the water shift makes a difference.

I also used solely RO water for many years because my well water is so salty/hard. But since I've shifted to a 10% mix of my well water with RO water I'm getting overall nice leaf growth on many of my plants.

 

[Justin]

50-100ppm of fertilizer is also on the very low range. suggest upping the fertilize, and as Goldenrose said you should make sure the fertilizer has calcium and magnesium, not all do. Cal-Mag and pH adjustment are very important if using RO.

 

[Kavanaru]

I have been using RO water with 120-150ppm Peter's Excell with good results, however, after changuing to MSU Formula for RO many of my plants starting having similar problems as treefrog's plant. mixing with 50% tapwater has helped to start solving the issue...

 

[PaphMadMan]

This looks like Iron deficiency to me. Calcium deficiency at this level would probably show some pitted leaf tissue, the beginning of necrosis. Or some other nutrient could be the problem, but no matter which it is, the cure is the same - make sure your pH is correct and increase fertilizer level, including micronutrients.

 

[goldenrose]

What fertilizer are you using? Does it have calcium & trace minerals? Interesting, I can't see how one formula is going to fit the needs of all orchid plants.

However if the pot pH is too high or low, then calcium (even when present) can become non available.
Iron tends to drop pH too, and also competes for phosphate.

It's interesting to see individual plants reacting this way (I'm sure Treefrog is more concerned than "interested") so we'll see if the water shift makes a difference.

I also used solely RO water for many years because my well water is so salty/hard. But since I've shifted to a 10% mix of my well water with RO water I'm getting overall nice leaf growth on many of my plants.

Good reminder Rick. My well/tap water is hard & I would think high in iron, I can't remember having a plant response as Treefrog's. I don't fix it if it's not broke. I might make slight changes here & there but if it were just a single plant I would not be switching back, why not just make a little special brew for that plant?

 

[gonewild]

I have been using RO water with 120-150ppm Peter's Excell with good results, however, after changuing to MSU Formula for RO many of my plants starting having similar problems as treefrog's plant. mixing with 50% tapwater has helped to start solving the issue...

Is that 150 ppm of nitrogen or total the nutrients?

 

[Kavanaru]

Is that 150 ppm of nitrogen or total the nutrients?

Nitrogen...