why does fungus love my oncs?

[seagull]

so i have 2 oncs, 1 is a little baby one with frost damage from shipping, the other i got in september and is larger
so the larger one is a bit odd
it came to me in sphagnum moss which kept molding over
i applied fungicide but eventually swapped media for bark/clay so the plant could have healthier roots
its largest pseudobulb is wrinkly and a few of its outer leaves are dying but it is sending out new growth so i'm not too worried
but it has some whitish crusty stuff on the largest bulb
i think it's more fungus

meanwhile the smaller guy has a bit of spongy yellow/white fungus (its in bark/clay too) and i applied fungicide

what is going on??

[estación seca]

Photos would help a lot. Whitish crusty stuff could be scale insects or mealybugs. There aren't many white fungus that attack living plants. It could also be salt buildup from high-mineral water.

Spongy yellow/white fungus - on the plant? On the bark?

[MrHappyRotter]

Increase your air flow. Make sure the pots and media are open enough that air can be exchanged around the roots. Also, make sure there's a light breeze or fan going around your plants to help keep the air moving.

Perhaps give them brighter light.

If your mix is developing fungus very quickly, that's a possible sign that it was bad quality to start with.

[Optimist]

Maybe some more air movement through the roots, and a fan to send more air around the plants. Many people forget that air movement is a requirement. You can get small clip on fans, some solar, at a lot of places. Air movement through the roots will cause less "muggyness" which might help with the fungus.

A thing to remember (maybe) is that fungus spores are in the air. If you have an indoor grow situation, possibly you can put some kind of filter over your heat ducts or air vents and then do a thorough clean of your indoor space. It would not be strange to consider that the spoors may not be of your doing. They could be coming from a moldy basement down the street or any other situation.