Brown rusty looking dry spots mid flower

[vick]

Trying to figure out whether this is light burn or Cal/Mag def. It only shows up on some higher leaves in some of my plants. I'm at 64 days in hydro with the lucas formula. PH 5.8 and ppm @ 960 right now.

 

[Guerrilla]

i have used this for a while maybe it will help someone. lways a good sheet to have around

 

[wg]

Hey my friend, that's not light stress.. it's more than likely calcium. Calcium is a pain in the ass in hydro because over 5.8 PH it starts getting locked out.

PH Chart for you


And why I believe it's Calcium (your leaf tips are curling as well, heat / light stress would cause them to canoe.. clawing is nitrogen excessive or calcium)

View attachment 172524

 

[vick]

Thanks guys. I have some calmag+ that I can add to the soup and I'll keep the ph at 5.5.

 

[namvet25]

http://www.growweedeasy.com/marijuana-symptoms-pictures Calcium and phosphurous def.:smokebuds:

 

[vick]

Great references. Really needed these. I'm guessing I locked them out before my last flush. Thanks again!