I have this happening also,
It started with one plant a day after watering all outhers were fine.
I went Fishing Today for the first time In two years to my favorite salmon hole.: and left my girls alone for the first time. Came home and found that seem to be happening on more leaves on outher plants.
since i left this am and everything was fine added 5 cups water only to the three in question, near dehumidifier, they always use more H20. and planned my watering after lights came on with the foxfarm nute program for 8week
9week schedule using their dirt i might add. everthing has been perfect up untill this.

can anyone help stinkbudd and RoosterTail solve this fast, 4weeks to go????
thanks in advance,
roostertail Reviewed by roostertail on . Will someone look at these pics and tell me what's wrong? I have some ladies growing in soil. They are in week 4 of flowering. The pH runoff is between 6.5 -6.8. The first pic shows what happens first. The second pic shows the progression. It always starts at the veins of the leaves. The tips and edges are fine. I noticed it begins at the bottom of the plant and works it's way up, only affecting the large fan leaves. I fed them with Bonicare's pro-bloom about 4 days ago and no improvement. Rating: 5