Spots on my phal

[Roberta]

[QUOTE=malteseproverb;871338
The strangest is thing is how the yellow spots and pitting only appear where the sun hits the leaf. Even the most affected leaf is clear from these symptoms where another leaf covers it from the sun. The oldest leaf on the plant is totally unaffected and also completely covered from the sun by another leaf (you can't see it in any of the attached photos but it's underneath the most damaged leaf).

[/QUOTE]

The most damaged-looking leaf also looks rather old... soon it will drop naturally no need to remove it. For the others, you may have hit on the problem... some of that does look like sunburn. I think that you will want to move the plant to where it does not get direct sun. Won't help the existing leaves, but new ones likely to come out clean.

[estación seca]

It does look a lot like the disease in the link you provided. I'm not sure what it is, but healthy plants are less susceptible to diseases. I would try to isolate the plant and keep them warmer.

[malteseproverb]

Wanted to update this thread in case someone sees similar spots on their phal. It was just sunburn. I really should have connected the dots. I moved it to a sunnier spot just as a period of cloudiness ended when this first started. I moved it to an even sunnier spot when ES said it should be warmer and then it got worse. I've since found an old pic I had of another phal that suffered sunburn that has identical spots. But I finally confirmed these suspicions after leaving it behind a sheer curtain. All the symptoms have stopped progressing, and it just keeps pumping out blooms.

[greenpassion]

Glad you found the problem.