Please save my violacea seedling! Severe chlorosis
 

My blue Phal violacea seedling's leaves have been on the pale side since I got it (8 months ago).

It's been in s/h, under lights, with a heat mat.
Fed rainwater + fertilizer at 125ppm N, +magnesium sulfate

When a new leaf that was just peaking out went yellow and died, I thought it might be a Calcium deficiency and got Calcium nitrate.

I have four other phal seedlings doing fine under same conditions.

The condition was still worsening so I went for the sphag 'n bag method and removed it from the lights, placed on warm window sill (26 C, 78 Fahrenheit). It's roots are in a poor state too. Used some rooting hormone and dilute solution of KeikiPro.
After two days the remaning leaves are almost completely yellow.

What's the problem? Can it be saved?

I'd really appreciate you're help as I'd be devastated to loose this plant.

Try growing it mounted instead.

Mounting can be great but I doubt if this can solve the problem? I don't know what is going on with this plant but the newest leaf is also yellowing and that starts from the crown?
I'm almost convinced this is a goner...

Nicole

I think mounted would dry and die unless it is very humid. I feel the 2 larger leaves will die anyway... would pu it in a greenhouse box and keep it humid - mist not water

Mounting won't fix anything..

What's the pH level of your water? I'm thinking nutrient deficiency, make sure your pH is not too high.. but then it's strange that only that one is affected if all the others get the same treatment

You said it was fairly pale when you got it? Perhaps it's just a dud plant, you get them sometimes in seedling populations.

P.S. I wouldn't throw any more hormones on it, it's mixed up enough as it is!

the ph after fertilizer is about 6.2/6.5, i always measure it. And yes, thingz were looking up for a while when it started growing a new leaf, then that died from the crown.

Thanks for your suggestions. I'll just put it in a humid environment and hope for a miracle.

You might be right about the plant being a dud, it's been struggling ever since i got it, plus the vendor i got it from turned out to be untrustworthy.

Update:
VIRUS?!

The seedlling eventually lost both of its bigger leaves. The smaller one seemed to be stable for a while, then it suddenly developed yellow markings. I think it happened the day I put it in a slightly warmer spot. The pattern seems virus like to me. Do orchid viruses respond to warmth? I'm now extremely paranoid that my other orchids may have caught it.
I threw what was left of the orchid away. By the way, the meristem was completely brown/rotted/dead.
Please have a look at the pictures and tell me if you think this was a virus.

Thanks