Burnt leaves and black spots. Help!

Plant was vegged outside and is in the 5th week of flowering inside under 400w hps. Leaf edges and tips are starting to burn at the top of the plant along with yellow stripes and some black stuff on smaller leaves. Assuming a nute lockout I immediately flushed the soil with water phed to 6.5 but the symptoms seem to be still spreading. The is my first grow so any advice is appreciated

Looks like you might have some powdery mildew going on as well.

Flushing may be making your issue worse, making assumptions of lockouts is a common mistake where lockouts are much less common. More commonly we just don't have enough of something. When the plant starts to flower the need for feed increases and the soil is becoming depleted. Tell us about your soil and feeding regimen. I suspect the beginnings of a potassium deficiency.

Aside from that powdery mildew (PM) is about to become your biggest issue. You want to raise the pH of the leaf surfaces. If you have been foliar feeding STOP IT. If you must spray your plants then make sure the pH of the spray is very slightly alkaline (7.5). This prevents creating an acidic environment conducive to PM. Products like Green cure basically use a base to raise the pH of the leaves, some people even spray with milk (gross). Actinovate and serenade are also handy but what you really need to do is fix the environment. Too much humidity is causing the PM. Sometimes this happens when the lights are off and the temps drop causing the RH% to spike.

My soil is pro mix for flowering plants. I feed with half the recommended dose (3/4 tablespoon) of miracle grow bloom booster 15-30-15 in 1.5 gallons of rain wateronce a week. And water with rainwater 1.5 gallons every other days

I have no exhaust or intake fans just a rotating one. So I have to manually exchange the air in the tent. Definitely gonna invest in a couple inline fans

Your having the Same issue i just faced and like you in thought it was nut burn, turned out it was light burn. Try moving your lights up 3 inches and watch over the week if it spreads.

I’m on a small phone but is that powdery mildew I see? How high is the light? Are you adjusting the pH of the rainwater?

Mafiaal said:

Your having the Same issue i just faced and like you in thought it was nut burn, turned out it was light burn. Try moving your lights up 3 inches and watch over the week if it spreads.

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Reporting back! I believe it was light burn as I have moved the light farther away and it seems to have stopped. . Ty everyone who chimed In y'all really helped a new grower out

hotrodharley said:

I’m on a small phone but is that powdery mildew I see? How high is the light? Are you adjusting the pH of the rainwater?

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Not PM, but residual sulfur from a broad mite problem in veg. Ph of water is 6 which seems low but if I try to ph up the plant reacts badly so I just leave it