How strong is the grow light? Could the leaf be burned? Or burned from where it was before? If it happened under the grow light, maybe move it out to the edge where it is less intense.

The plant does not look very good. Is it in spaghnum, or is that just a top dressing? Does the pot drain ok? It could be rotting, though i agree the yellow pattern is odd. My guess is the light is too intense. Janine

It has been declining very slowly for 4 months now. Starting with root rot at purchase time.

I have about ten phals, all doing well, except this one.

Some of my phals are in just bark, one is in sphagnum, and a few, like this one, are in 50/50. I grow well in both mediums.

The grow light is just one grolux tube. I have three minis growing under it, two of which have been there since purchase, and one which was recently moved there. None of them had trouble with light intensity.

These phals grow more quickly than my other phals. The fast growth rate is the reason I moved this one off the windowsill and under the light.

The yellow is spreading on the leaf, and resembles the leaves that were shed prior. I can only assume now that it has decided to drop the leaf.

Changing it to orchid bark for phalaenopsis might help. It looks bad, but I've had orchids on the brink of death come back. It is probably stressed from being knocked over. I also read in a book that you can actually make false roots out of wire until it grows new ones. Send me a email and I will be able to tell you which book it's in. Sometimes orchids just die anyway no matter what you do to save it.

This one did not do well in bark.

The roots were attacked by some kind of mold or fungus after being potted up in sphagnum. After killing the mold I switched to bark. The roots then turned blackish at the base and died slowly. They looked scarred and shriveled. At the moment it may or may not have an inch of functional root left.

I have found the 50/50 mix very forgiving for small/sick phals.

Wire roots are not going to be useful in this particular situation.

It is nice to hear you have had success in rescuing sick phals. I havent thrown this one away because I keep expecting it to turn around.

If the phal has no functional roots left it would be worth a shot. All it needs is a functional root to help it out a little. Sounds like you're dealing with root and base rot that has gotten worse. I know you said it was starting to rot when you bought it. Hopefully it will get better for you. I've had a couple of rotten phals before. Most of them didn't make it. :(

It does have one green leaf, so instead of messing with it more, (and shocking it) just wait and see. You might dust rootone on the plant base where you can reach it. I had a couple come to me in bad shape, rotten roots, etc (in spaghnum) and repotted in bark and dusted with rootone. All four now have new roots coming and are going to survive, i think. I also misted them a couple times a day to keep them happier. In my case the leaves were shriveled, not yellow. Janine

The 'wire roots' are for stability in the pot, which can help a phals roots grow. But it wont encourage root growth where there isnt any, and it wont help the plant absorb water.

I will probably just give it minimum care and leave it alone, as that seems to encourage root growth better than being fussed over. It is in a good spot for growth now. They really love the grow light.

Also, the initial rot was taken care of a while back, so all it needs to do is regrow. It had two new roots which died, but they were not mushy or brown. They shriveled because they did not like being buried in the medium.