You could have a pH issue there, but I think that is heat stress. 90 is too hot for a grow room. Put a fan in there if you haven't already, get the heat out. Maybe move your light up some.
polishpollack Reviewed by polishpollack on . I need help urgently..my plant is dieing After a month and half of taking good care of this plant here come the problem. as you can see the brown spot is all over the leaves...starting from picture 1 brown spot start showing mainly from inside out picture 2 starting showing some yellow spot within the brown spot then picture 3 the leaves starting to die out. the picture 4&5 is taken from the tree...this symtom is spreading all over the tree and its killing my tree..one of the plant is turning all yellowish...I need help urgently to Rating: 5