I have a U. quelchii that's chugging away in a highland terrarium, and I'm wondering if I should fertilize it and, if so, how much/at what concentration. It's growing in live sphagnum moss with some perlite added to make the substrate a little lighter. At first I fertilized with orchid fertilizer at 50ppm N once every few days. On the one hand, its new leaves grew faster; on the other, it dropped both the leaves it arrived with and a leaf it had grown somewhat larger under my care. I stopped fertilizing, but now it grows far more slowly--which makes sense--but so slowly that I'm wondering if I should fertilize again. Is it likely that the fertilizer made the plant drop the leaves, or is something else likely to have been the culprit? I don't think it's temperature or humidity, since this plant is growing next to happy highland Heliamphora (such nice alliteration). I know U. quelchii often takes a while to settle in and tends to grow slowly in many situations for years, but given how fast it was growing before I wonder if I should change something. I could also dilute the fertilizer I use even further, although it's already pretty dilute (50ppm is 1/4 strength), or I could fertilize less often. I will note that the sphagnum growing in that pot and the other ones I fertilize grows incredibly fast relative to unfertilized pots (I assume that it's still going through leftover nitrogen at this point).