(Gur/Cat) aurantiaca hybrid acting sun sensitive
 

I have a relatively recently acquired Gurianthe aurantica hybrid (properly LC Fire Dance x LC Caribbean) below an East, slightly Northeast facing window. According to my $30 light meter the light only gets to the 3500 footcandle range for about two hours in the morning, which makes sense as I have a tree blocking some light. Thus there is a supplemental light overhead. Most of the day it is between 1500-2000 footcandles. The humidity stays between 50-75%, but I won't exclude the possibility of a stray hot dry breeze.

The pseudobulbs and lower parts of the leaves have turned red on sides that have been facing the window, and there's some speckling on the leaves. Yet none of the other Catts and Den Nobile are acting like this. The leaves on the others are even a little dark, and I had been thinking of upping the supplemental light.

Is there something wrong that could be causing this?

I haven't got this particular plant, but certainly there are catts or catt-related plants that develop red or even red/purple regions where light is relatively bright ----- or bright enough. Not only is there nothing wrong ------ it can be a desirable sign.

For example ----- the plant in this photo below is doing excellently. It's a Rth. Free Spirit 'Laina'. This photo was taken earlier this year, when it had only 1 sheath. But now - not shown in the photo - there's currently two sheaths, since an extra pseudobulb formed between then and now. Pretty sure I'll get a flower soon - as the base of the newest sheath is starting to thicken up with active flower spike/bud growth. And I can see the promising outline shape of a spike/bud. The main thing to notice is the red/purple colour on the pseudobulbs. That's no problem for this plant.

So --- if your plant is not getting burned, then no need for concern. Maybe you can take some closeup digital photos of the regions ----- just for double-checking.

http://www.orchidboard.com/community...1&d=1549061857

Leaves/bulbs turning red is a good sign your plant is getting the amount of light required to bloom. Its a good thing!

Thanks, that makes me feel much more comfortable! I got this guy as a tired dry back bulb division, so I've been worried and babying him ever since he arrived.