purpleing on cattleya leaf

[lobotomizedgoat]

I got this Rlc. Hawaiian Lightning last June. It bloomed a month or two after I got it, was repotted after that, and has spent the time since growing roots. It was getting less light than my other catt so when some room opened up I moved it closer to one of my grow lights. A few days later I noticed this purple blotch appear, as well as a fainter bit on a leaf further away. Some of the leaves of my other catt receive similar exposure have not changed beyond one lightening a bit.

I angled the plant so the light was less direct and that seemed to halt further discoloration. Over the last few days I feel like the area may have changed in color a bit again. It may be getting some sun at sunrise now, filtered through a screen door, but I haven't been around to check.

Aesthetically, I don't mind the change but I want to double check that it is indeed from light exposure and not disease or undernourishment. Also, if it is from light, how important it is to reduce its exposure?


Culture: 65-75° F, ~60 % RH, med bark, slatted terracotta, flushed with tap water every 5 days, fert ~2/month at ~100ppm N, sometimes misted in between waterings