***Help*** Yellowish marks on leaves, light burn?

Hi guys, noticed these white/yellow/brown marks on the leaves. Can't quite figure out what's caused it

Anyone seen this before and know what it is?

It has come through in the past two days

I have a par reader, no light is over 1500umol (either between 950-1250) and I run co2

Is it possible to still get light burn?

Not a pro but i think the fans in 2 nd pic show potassium def

Maybe mag

Everything is a guess and your not getting replies because you gave nothing for info on grow

Since we’re guessing here because you’ve given zero info on your grow , my guess is you are under feeding your plants

Not related to the yellowing but another observation. When you choose material for netting you want something that doesn't shed fibers that can end up in the buds.

Feeding house and garden range (coco)

EC of feeding is 2 (use cana calmag to harden the water prior to adding A&B due to soft water)

Room temp 30c & humidity is sitting around 60%

Co2 ppm 1400-1500

pH of feeding is 5.8

Have done a few grows the exact same and never had this type of issue before

xtsho said:

Not related to the yellowing but another observation. When you choose material for netting you want something that doesn't shed fibers that can end up in the buds.

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Yeah am careful of the fibers, generally don't get an issue