defiency

is this potassium deficiency, grown in promix hp under hlg 550 and use general hydroponics

Hey Fellers, Been dealing with this problem for about a month/6 weeks now. Thought i had it beat then when i flipped into flower at the beginning of last week it came back with a vengence. my first thought was nitrogen, and second was potassium but apparently i was wrong. Grown in fox farm happy...