Light green spots on phal leaves
 

hello fellow orchid lovers! can someone help me with my rescue phal? i found this little guy on the clearance rack about 8 months ago all shriveled up & with root rot. well, i nursed it back to health and for a long time its been doing great. it grew lots of new roots, 2 new leaves, and even put out a spike and bloomed 5 flowers.
these spots started some time this past week (the spots weren't there when i watered last friday)...

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Untitled by big_cutie_monster, on Flickr

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Untitled by big_cutie_monster, on Flickr

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Untitled by big_cutie_monster, on Flickr

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Untitled by big_cutie_monster, on Flickr

this phal sits in a north-east window and gets about 30-45 minutes of morning sunlight then bright but indirect light the rest of the day. it is potted in better gro orchid bark phaleanopsis mix. potted up about 8 months ago after brought home from store. i water every 7-9 days as needed & usually feed immediately after watering. i water it by flushing the pot with temperate water, then i use a small peice of paper
towel to dry the leaves and crown area. also, this plant along with 2 others live in my bedroom & i run a fan at night,'so they get plent of air circ. additionally, none of the other 3 phals in my home are having these symptoms and one of them sits only inches away from this one. in fact, none of the other phals that have ever lived in my home have ever been sick. any advice is greatly appreciated. thanks.

Difficult to tell, but it can be a few different things:
- acarians… spidermites are not your friends.
- a fungus (maybe, can be associated with spidermites)
- carency (but it does not work well with the symptoms)

check for spidermites.

check your other plants, it may not be the only one.

definitely not spider mites. just watered everybody else & they all look good. even the one who sits by this one. if it is bacterial/fungal then what to do? can i wait and watch? or should i treat aggressively?

Edit* also, what is the best medicine to put on this?

Umm....sun tan lotion?

I have the same problem with my phals, and only the phals. Eventually, these spots will become yellow, then dry. Often they will spread and discolour the entire leaf, later killing it.

I also suspected spider mites, but could find no signs of insects of any kind. As a precaution, I've been giving weekly sprayings with a miticide.

I've been reading up on mesophyll cell collapse, and some of the online photos look very much like yours. Since it's been especially cold this winter, it's very likely that droplets of cold water became even colder on the leaves, and damaged thr cells in the leaves..

One of my affected phals has put out a new, perfectly green leaf. Now that it's warmer, and I'm careful not to get water on leaves, I expect to have a blemish free summer. But if it's bugs, they could come back.

It doesn't look like spider mites to me. It does however, look like some kind of sucker bug. I can't tell which one but I can give you some insight as to what I'd do.

Take it out of the pot and check the roots...inspect it to see if you see any "creatures" in there. Then repot in a nice clean pot with new mix.

Hit it with a systemic like Spinocid or Bayer for ornamentals.