sudden brown spots and leaves

[verucasalt]

here are more pix of our sick girls see previous post . indoor grow under 600wled in happoy frog soil using fox farm nutrient trio ph 7.0 grow was fine until 2 weeks ago started adding ph down to their water. did i over do it? thanks,Veruca

 

[Mr.furley]

Hey verucasalt,
how close is your light? and did you test your run off PH?

 

[Sammy]

Like mr. Furley said check your pH runoff I bet it's way out probably low if I had to guess good luck good looking plants

 

[verucasalt]

runoff tested 6.5 ph light is 18 inches away from plants. all during grow we kept the light about 12 inches and had no problems this just cropped up in the last two weeks and seems to be getting worse. Veruca

 

[verucasalt]

oh btw seeds are white widow fem.

 

[berrypilot]

🌱 It looks like the damage is worse on the middle parts of the plant. Are these the parts that are closest to the LED grow light? Some LEDs are really powerful and may need to be 24" or more away from the plant to avoid burning. Additionally, certain plants, for example some Indica and Auto-flowering strains tend to be very sensitive to light burn.

I know you don't think it's the LED being too close, but if you get stumped, I encourage you to try putting the LED up a few more inches to see if the symptoms stop spreading as fast. I only say this because I read on the LED page on the GWE site that it's typical for plants to get more light-sensitive around week 6 of the flowering stage, and LEDs may need to be kept further away than was okay earlier on in the plant's life to avoid light burn. It's because around week 6 of flowering the plants stop making any new leaves, and the old ones can start to get overworked and die earlier than they should. 🌱