Weird looking orchid leaves
 

Hi! It's been a while, but I want to know if some of my orchids are healthy or not (and what can I do about them). 1. It's a Phal. japonica that has slowly lost 3 leaves this year.
2. An Onc. Sharry Baby that's getting more and more spotted (but hasn't lost any leaves).
3. A Paphiopedilum x Nitens that lost some leaves with weird markings but right now it seems to be doing ok (but the remaining leaves have a weird texture)
4. And a NOID Zygopetalum that is losing leaves, getting spotted and bloomed some weird looking flowers (a lot smaller than I remember).

Thoughts?

The Paph is losing an old growth that already flowered. Eventually the leaves die one by one and the old growth disappears.

Most of the other plants look underwatered to me. The Zygo has pleated growth, which is characteristic of underwatering. I don't know what your water is like, but with high dissolved salts and underwatering, leaf tips on Oncidiums can get salt burn. It looks like what is happening with your plants.

I have also read spotting on Zygos can be minimized by using pure water and giving high humidity with good air circulation.

Agreed, ES, however, my Zygo is in high humidity with a fan blowing on it and it still spots. Sharry Baby also. I would flush them both with clear water and not worry too much. The other problems are beyond my expertise.

I don't have a lot of experience with Paphs, so that's good to know.

The pleated growth in the Zygo was already there when I bought it (I knew it was underwatered, but I really wanted to buy it anyway). I use RO water with fertilizer at around 25 ppm of N to water twice a week. But I do agree that I stopped flushing every month as I used to do, now I flush every 2 months (I've bought a lot of orchids recently, and flushing everyone is getting tiresome).

My humidity this winter has been tricky to keep up now that my orchids are in a much larger room and winter here is really dry (but I keep it between 50 - 65%).

I've got 2 small PC fans running all the time and a big tower fan that I turn during the day while the humidifiers are on. But now that I think about it, the spotting is a lot worse on the orchids that are the furthest from the PC fans, maybe I should put more fans there.

---------- Post added at 12:47 PM ---------- Previous post was at 12:43 PM ----------

Anyone has any input on the Phal. japonica? That's the one that is worrying me the most, those round spots look really suspicious to me. It has a great root system, I water it twice a week, but it's still slowly losing more and more leaves.