Coelgyne Finbriata concerning markings

[Longroots]

I've had this Coelgyne for years. I recently noticed these marking on it however which has made me worried. I tested it using Agdia years ago and it came back negative, I tested it again and it's still negative.

I cut one leaf off for testing, there's one leaf with some funky markings, and another which seems to have a similar formation appearing. Some leaves have some uneven yellowing. Obviously these drop their leaves over time, but I don't like the sort of mottled look. Finally, one set of leaves have come up curled. I'm unsure if this is a humidity issue, and I started noticing this when I put it under a stronger grow light.

It was pretty shaded, but now it's got something a bit brighter. Would this worry anybody else? It's one of the first orchids I bought years ago!

[estación seca]

How are you fertilizing? The plants look a little dehydrated as well.

[Longroots]

Fertiliser is currently at 60ppm with a mix of seaweed extract and cal/mag... and I've just realised my semihydroponic reservoir has run dry...

That will probably have a lot to do with the yellowing that has appeared fairly suddenly...

[estación seca]

60 ppm what nutrient? Seaweed extract has minimal nitrogen. How often are you watering?

[Longroots]

It's in semihydroponics so has consistent moisture always (other than just now!), and has been for about 5 years or so now.

I'll grab a high nitrogen fertiliser tomorrow. I swore liquid seaweed was high in nitrogen. It was specifically why I had been using it for a little while.

[estación seca]

It doesn't need high nitrogen, just some nitrogen. I suggest you go to the First Rays Web site and read about fertilizing before making changes.

[Longroots]

How about the black lines in a slight circular pattern though?

[estación seca]

Along the pseudobulbs? They develop black marks in wrinkles and at scratches. I don't think it represents a different problem.

[Longroots]

No, the black markings on the leaf in the third image.

[Dusty Ol' Man]

Originally Posted by Longroots

It's in semihydroponics so has consistent moisture always (other than just now!), and has been for about 5 years or so now.

I'll grab a high nitrogen fertiliser tomorrow. I swore liquid seaweed was high in nitrogen. It was specifically why I had been using it for a little while.

I would suggest you go to Ray's website and read all the information on plant nutrition and fertilizer. First Rays LLC