Question Is this potassium deficiency or nutrient burn?

I'm getting a bright sunburst yellowing and burnt tips in my flower tent.
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Not as bad on the GDP but starting
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It's beginning on the newer upper leaves.

My feed was @ a 1.0ec. I bumped up to 1.2, dropped N and raised K some, but I was wondering if you all think it's a K deficiency as I'm thinking?
Or did I somehow burn them @ a 1.0ec using ro water and GH trio?
 
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