Bleaching on leaves

What is causing these odd stripes and necrosis on my fan leaves? Autopot system, in purple cow soil. Was feeding very light amount of bloom, bud, cal/mag in water. Now just ph 6.5 water. I did switch the LED lights from Veg to veg and bloom, but was convened it was light damage so they are now just running on Bloom only. This is happening on both plants I’m growing. One is a real stunned Gorilla glue that is near the end of flower and on this amnesia haze. Both are ILGM auto seeds.

I wasn’t sure if it was the light, nutrient burn, a trace minerals issue, or a potassium issue.
My gut was light because I had switched my LED to both the bloom and Veg setting and it seemed fairly bright. I saw some stress and then just switched it over to bloom only. It had been on Veg it’s whole life up until that date.

Should I just keep it on Veg since the autos had their whole life under that lighting?

Thanks for the reply.

pic shows major nute overdose

It’s in soil, but possible. Although it’s hasn’t had any additional nutrients added for a while, just ph 6.5 water. Didn’t really see this start until after the lights were adjusted to a higher setting, so I assume it’s more about the lighting. It’s just strange because it’s not burning the tips of the leaves, just these really strange stripes in the middle of the leaves.

Don’t think it’s nute burn. Tips are fine and that’s where it starts.

Start by adjusting your lights height and see how they look in a few days. Check the manufacturers manual and go from there.

Also, post a pic of your whole plant under natural lighting, if possible. Gives a much better insight of your issue.


I’m starting to feel it’s the change is lighting from Veg to Bloom/veg setting. I’ve pruned the leaves that were getting this stripe pattern, and see see a couple that are starting, more visible under the blue Bloom lighting. The plants are now under bloom only. I’m getting this on both autoflowers right now. Which also leads me to think it’s the lighting over nutrients.

Thanks for the input. I can move my light up any higher, so I may try to put it in a dimmer if it doesn’t improve in the next couple days.

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It could very well be the light, since it’s only the upper growth which appears to be effected. 90% of the leaves look good. Might need a light feed soon though. Something with a little bit of nitrogen. When was your last feed? There is some visible nute burn on a few leaves.

Most people recommend you use both veg and bloom switches at all times for that extra light intensity, but if you’re out of headroom, you can run both and just dim it down a bit. Keep checking everyday to find the sweet spot.

Other than that, they look pretty good to me.

Maybe @Covertgrower could give some valuable input. Guy knows his stuff!


You guys covered it pretty well.

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Looks like PH issue to me. I’ve been there. What is PH of runoff?

The ph on the run off is about 7.6. So it could be the soil PH as well. Thanks for the suggestion. This is purple cow soil, not inert medium.

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7.6 is definitely high. I’d start lowering the PH of the water going in and try to get the runoff number down. Either that or do a straight up flush.