Thanks John. I grow year round indoors under T5HO lights because my climate (wind, rain, fog year round) doesn't support citrus, or much else for that matter ;-) The room I have them in has 8 other citrus trees and 37 plumeria. The lights are on 12-14 hours a day and during that time temp is 88-90*. When lights are off 72-74*. Humidity 42-44%. I have four fans blowing constantly and irrigate with rain water.

Would poking more holes in the sides of the container help? Any other suggestions? Really appreciate your input!

Nancy how do you keep humidity that low? Night time is a bit lower here but daytime can get as high as yours. Humidity not under 55% but average is 70%

I use a dehumidifier. My greenhouse is in a basement and I'd have mold without it.

Stilll looks like edema to me; you can google it to study cause and cure. I have virtually no real time experience with edema as all my trees are outdoors in ground; but I do recognize it when I see it.

Thanks a lot John. I'll need to do some homework :-)

Treated the Dancy to Thanksgiving Day gift. Since my trees are grown indoors all year round they don't know what season it is. So I transplanted this guy into a 7 gallon container which I studded full of little holes for better drainage. Roots looked great and soil moisture just right. But will see if this helps any.