Help: not sure what deficiency or maybe burn?

[Dadsweed]

Hey haven’t posted in a few months but have an outdoor grow going at the moment. Everything has been fine up until a week or so ago.. some of my leaves are turning yellow brown??? Any ideas would be greatly appreciated. My first thought was a potassium Deficiency??
Thank you

 

[Alafornia]

Look at the helpful links in my sig then go to "how to ask for grow support". There's not enough info to answer the question.