Thanks Sue!
I see this only on Caracas Candle so I was wondering if it's a trait or if it's a "weak" plant.
Now all DLs seems to be a lot better, but I check foliage everyday and if I see something I don't understand I ask on here or I check that wonderful PDF file someone shared on my thread on chlorosis.
The PH is about 8 I read many consider this a "slightly" alkaline soil, nothing to worry about, but I'll keep things checked. I was planning to order a kit for soil analysys, they are not too expensive.