What is this? Autoflower problem

Grow Support Autoflowers
1

20201005_092953
20201005_0929531134×2016 842 KB
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20201005_0929561134×2016 826 KB
20201005_092939
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not sure about this one? I’ve 2 autoflower plants in tent 4 weeks old just starting to flower in last 24-hours any ideas they are striped like markings

2

Looks like start of a cal mag deficency.

3

No I’m feeding calmag 2mls per ltr unless it’s ph problem maybe my metre is faulty