brown leaf spots

Hello all. This is my 1st post on here and it will be about my second grow. i have 2 gorilla glue autos in ffof/40% perlite, 3gal fabric pots, under electric sky 300 v2 in a 2x4 grow tent, indoors. Temp averages 80 with lights on. humidity was averaging 60% but since I discovered it could be...