Older growth showing issues, plant growth diminished. Ph and light distance good.

maybe, too much K? i'd shoot for 6pH. Being so close to the bottom range may or may not have a noticeable beneift, but it definitely gives you less room for error in that direction. always irrigate until a minimum of 10% runs out the bottom. waste water down the drain or give outside plants (not in a pot) a good boost. Too much P can also burn the tips. And, both p and k can lock out stuff that can cause the other symptoms seen in these pictures. I'd lean K, without looking at what you fed. you can investigate that and make a more educated choice. the plant looks a little lush. if it starts to claw, reduce overall concentration of fertilizer as well. It's difficult to be sure looking at plants under a grow light. so, if/when you remove a leaf, always good practice to check it out under normal lighting. i've got a nutrient spreadsheet that should work with your dry nutes (d/l link in profile comment section, sort by date)... should handle specific gravity? lol never had to use that function to verify it. manic botanix also has an online ppm calculator - it also more elouently explains when you need to use specific gravity. if k is way over 200 added up across all products used, i'd bet money that is the issue. Definitely some imbalance in the formula.