I get that same thing but worse ....it looks like black spot....a fungis
VapedG13 Reviewed by VapedG13 on . Browning around leaf viens this plant is in FFOF soil, inside, last runoff check was in the 6.5 range (going to check it again tonight). have been feeding her Grow big at 5ml per gallon ph to 6.5. Just turned the lights to 12/12, temps are around 82, and overall she looks really healthy, have just noticed a few fairly new leaves that are showing this symptom. Rating: 5