Plant problem, recommendations are very welcome.

Hi RIU members!

Few days ago I saw some spots on my fan leaves, all what I can say that I'm growing in greenhouse, humidity is a bit higher than it should be, about 60%. Temps are 30+/- 5 degrees per celsius in days and 15 in nights. Maybe you can see that there is a bit mold because of high humidity? What do you think? Today I made another air entrance, so air can circulate more.

Very early nute burn, ease back on the nutes for 1-2 weeks, and water well ...should recover OK

Thought it's Calcium def, but ok, will back on the nutes, thanks.

Looks more like cal/mag to me and I see the white stuff on edges when I blow up the pics. It doesn't look like powdery mildew but maybe some other type of mold. I don't recall seeing a mold that grows in that location so maybe just dried crud from watering? I would scope it for sure. A diluted hydrogen peroxide spray would probably take care of it. Forget the ratio but let me know if you need it, I've got it written down somewhere.