Beginner Gardening: What caused these black patches on my Bodi tree leaves?, 1 by Bhodichitta

Bhodichitta wrote:

Some of the leaves on my bodhi trees developed some black, almost burnt looking patches on the leaves.

I have been keeping two bodhi trees in my "fish house" (a room 80 degrees F @ 80% humidity) and these trees and cuttings have been growing well under a 400 watt agrosun gold HID light.

I did recently move the trees outside during the days a few times recently when the temps were above 55 outside.

Might the move to the colder air/draft have caused this problem, or is it the suddenly stronger direct sunlight or some other thing like a different PH watering that could have caused this??

The trees are doing very well, but I would like to know what caused this so I can avoid repeating it.

Thank you in advance :)