yellowing on the ridges/tips.

[Guest]

I cant really tell what this is by reading the help thread thats stickied.

potassium , magnesium, early calcium? or zinc? Im currently feeding them all fox farm grow big at 1 teaspoon per gallon once a week along with 1 teaspoon of cal/mag plus. not all of these plants seem to be showing these symptoms though. only about 6 out of 11.

soil, 6.0 pH, 1 1000w hps. hashberry and k2 clones in the picture. temps 83 degrees until I can get my AC unit hooked up. If I left out any information please tell me, will post it.





bigger picture. I know there is 3-4 spots of light bleaching on the 2 leaves, but im interesting in the other yellowing/tips.

 

[Blackvelvet]

I bet your using tapwater. Drench once with 1 teaspoon epsom salts per gallon of water. Feed with every watering. 6-4-4 grow big? Use 1 1/4 teaspoons per gallon + 1/2 teaspoon cal mag plus per gallon. (~110 ppm n) Adjust the fert water ph after adding everything for best results. When applying the fert water, you want runoff out the bottom. 20% of what you add should be runoff.



.

 

[Core]

just get that ph up to 6.3 -6.5 and i'll bet all the troubles will go away...damaged leaves wont heal though...

 

[Rosy Cheeks]

Most likely a nutrient lockout problem due to low ph. It looks like a deficiency, but in fact the plant is having difficulties assimilating alkaline nutrients due to the acid environment.
I'm no foxfarm expert, but on their web site they recommend a ph (for their soil and soil nutrients) of 6.6 -6.8. Cannabis prefers a slightly acid environment (below ph 7 being acid, and above being alkaline), 6.5 - 7 is generally where you fix your ph. In hydroponics, you keep the ph slightly lower (around ph 6) in order to avoid root rot. As Core said, bring that ph up and see what happens.

 

[coolx]

first - definitely bring the ph up ... second - you say there's 2 spots of light bleaching? that would be on bottom pic, center right leaf? well then that must have happened a while back then, when that leaf was the top or closest to the light. So my q. is, when did the yellowing start? back then when your leaf got burned or just recently? (FYI - mg def can show either at the top OR the bottom of the plant as it is a moderately mobile element - it depends on the interaction of your nute ppms and the rate of growth. If you have a severe shortage and not enough nutes, symptoms whill show at the top first, a light shortage, bottom first.) But get your pH right first - like everyone says 6.5-6.8. I always had 6.5 in soil.

 

[Guest]

the light bleaching happened about a week ago, the yellowing happened about 2-3 days ago. Thanks for the help guys, will fix my ph.