Now that you say that yes it does....Almost looks like bug damage or some fungi
Can you confirm there are NO BUGS in your room or on your plants or even in your medium?used the same nutrients all the way and I didn't have the problem until 3 days ago.
You bug bombed your grow room? Twice a month?Ph is around 6. No bugs, bombed the room twice a month.
You bug bombed your grow room? Twice a month?
Can I ask why? Did you have a bug problem previously?