Most of my WW plants start this about 20 - 30 days. It reduces the yield, but plant appears healthy otherwise. My other strains (Amnesia Haze, Maui Waui) do not show this problem. Is WW more PH intolerant?
I found WW to need proper PH to look great.
It would be easier to help you if you filled out my support ticket in order to give us some background on your grow methods.
Strain; Type, Bag seed, or NA ilgm White Widow fem
Soil in pots, Hydroponic, or Coco? hydro
System type? deep water culture
3 gallon pails/aerated
Jungle juice 2 part changed weekly
PH of runoff or solution in reservoir? 6.5
What is strength of nutrient mix? EC, or TDS 2ml Jungle Juice 2 part per gallon (4ml is standard)
Indoor or Outdoor Indoor grow box
Light system, size?6x100 cfl and 4x20 watt tubes about 2500 lumen sq ft all cool white
Temps; Day, Night 65 75
Humidity; Day, Night not measured
Ventilation system; Yes, No, Size simple fan
AC, Humidifier, De-humidifier, no
Co2; Yes, No no
Well then. you should be running a PH of 5.8. Your PH is too high.
@nd thing. Jungle Juice. Worst nutrient I ever used, and now that I know you are using that, and only at 1/2 strength; I blame the Jungle Juice compounded by the high PH. Every time I ever used JJ; I got the same looking damage to many of my fan leaves.
I know you said you had some doing well, so I don’t know what else to tell you.
Oh yeah, Too much humidity could also cause issues. Best to buy an inexpensive humidistat and make sure you dial in that humidity to proper levels. This may force you to install an exhaust system to draw in cool air and vent out hot humid air.
Hope this helps.