Possibly some type of leaf spotting fungus. The pictures don't look too bad to me. I grow outdoors in South Florida so there are always spots of one kind or another on my orchids, including fungus. If you can increase the air movement around your plants, that can help. Some people use a fan to move the air. Don't water in the evening because wet foliage at night encourages fungus. Make sure your fertilizer contains calcium. Calcium builds stronger leaves that resist fungus. You can spray once a month with a fungicide if you want. It can be a pain in the neck if your plants are indoors. You'll need to take them outdoors to spray. I find it's particularly important to spray vandas which can be very susceptible to leaf spotting fungus. Cut off any vanda leaves that have large areas of bad fungus (not the little spots). Good luck.

Tucker85, I'm beginning to think its some kind of fungus. No typical symptoms of bugs, I'm not ruling out a virus but I'm fairly sure its not. I'm thinking fungal.

I've turned up my fan in the greenhouse so there is more airflow. I just got through watering them all real good and applying some Physan 20. I don't like using chemicals but I don't see much choice. So all my orchids have been throughly drenched in the solution.

I only water in the morning or early afternoon.

How often should I treat when trying to get rid of the fungus?

Oh and for fertilizer I use First Rays K-light fertilizer and I'm fairly sure it has calcium. If not, no worries as on my non-fertilizing week I use some tap water diluted with DI and we have a good bit of calcium in our water.

The spots that are on the leaves will stay there. They won't go away. When I see a problem, I treat with a fungicide (Thiomyl) once a month for about three months. But it's easy for me because I grow outdoors. You may want to wait and see if it gets any worse. By the way, most leaf spotting fungus don't kill orchids.

The orchids are outdoors in a greenhouse. I moved them outside after many trips to the bathtub with individual plants to water them.

So this spotting fungus is harmless? That is a huge relief.

I'm hoping it's just a harmless fungal.

So a month later, the fungus stuff is still around, but as far as I can tell no one is dying. Mostly my carts and the vanda covered. My greenhouse is fairly damp which is worrying me as we approach cooler weather.

How are you watering the orchids? If the greenhouse is too damp make sure you are not adding more moisture every time you water. Does your greenhouse have some venting system to the outside? It would be good to have some air exchange happening. Our winters are much colder than yours but I keep my orchids a lot dryer in winter as the temps are much lower in my greenhouse. You may need a dehumidifier if you have cool temps and a lot of humidity.

I water my orchids with a nozzle attached to a garden hose using a gentle shower setting. Or when I fertilize I make up a 5 gallon bucket worth of fertilizer solution (Ray's K-Lite) and use a mason jar to measure out the appropriate amount to give each plant.

My tap water doesn't seem to bug the plants at all. We have somewhat hard water. The greenhouse is roughly a 7'x10' rectangle with two large vents I open up manually everyday and usually leave the door open also to help with the heat buildup. There is a box fan that runs 24/7 to keep air moving all the time.

The greenhouse is not 100%sealed from the elements so at the four corners there is a nickel sized gap from the construction. So there is no lack of air movement. It's a metal framed house with double walled poly but I'm not sure of the thickness. It was my mom's greenhouse which I've taken over.

It sounds like there is good air movement. I would do a monthly spray of Physan or something similar and possibly try watering with a watering can on the media, not wetting the plants down. Water dripping from one plant to another could spread the culprit around. I never wet my plant leaves but I do still get spots at times and can't explain why. I used MSU fert that does have calcium and our water has enough calcium also. But adding a Cal/Mag. supplement recently seems to have been making a big improvement. I still need some time to make sure the new leaves won't eventually spot tho.

Yours looks like tiny pin prick spots which I don't get so it does look like something different.