Dracula Lotax mark on leaf
 

I've had this Dracula in semi hydro and its roots all seem really happy. However, today I noticed a weird mark on the leaf. I'll post a normal image and the edited image to see how the discolouration is forming. A similar thing happened on the tip of another leaf but it halted. I've not fertalized it and I'm using exclusively rain water. It's on a North facing window that pretty much had the East side blocked from light also. I've tried to make it as humid as possible by sinking it in very low in the semi hydro pot, but when I can afford to I'll likely be making an orchidarium for it.

Looks a little like damage from a munching pest. But, how long have you had it with no fertilizer? At some point nutritional deficiency can't be ruled out. Dracs are really light feeders so it could take a very long time to see that, but it's possible. Others can advise on that better than I can because I don't think I have ever had a deficiency issue, at least not a serious one. I don't give my plants much, but I do fertilize lightly occasionally at least. (There is a difference between "very little, not often" and "none ever")

I've had it now for a couple of months. I fertalized it when I first got it, when it was still in moss. However, I have no signs of any pests anywhere either. I'll make up a really weak mix for it next time I refill the reservoir. With semihydro I'm VERY aware of how salt can build up very quickly.

A few months is not enough to get a deficiency issue, maybe after a few years... a very good Dracula grower that I know recommends about once a month for Dracs where she gives it to her Masdevallias (also beautifully grown) once a week. Very dilute for both, of course. So if that level is optimal, they can both do fine with a LOT less.

Also, humidity is not such a big deal if the plant is wet enough. And that might be an issue is SH. I grow my Dracs in plastic baskets with sphagnum, and they are sopping wet most of the time. Humidity is whatever Mother Nature provides, maybe 80% at night and 45-60% by day most of the time but occasionally down to single digits RH and HOT. Keeping them wet seems to get them through both low humidity and high heat episodes. In fact, I am amazed at how, even in summer, the big flat ones (like roezlii, woolwardii, cordobae for example) will be wide open in the cool of the morning, to partially collapse as the day warms up and then perk up again the next morning. Worth getting up early and visiting them with coffee in hand! Here's what greeted me last week...