yellow tips

Hey guys, So first of all, some info: 3.9gal / 14L autopots, 4 of them, and 12gal / 47L Reservoir Coco / Perlite 60/40 Canna Coco A+B, Canna Calmag Agent, Grow Genius MSA (Sometimes) 75% RO / 25% tapwater, my tapwater itself is too unstable, heavy PH problems, so mixing with RO Speedrunseeds...

Help! :) I have a purple haze auto that has yellowing tips on the leaves. Is this nutrient deficiency? Thanks in advance!!

Gelato by fast buds Organic Cocoloco Supersoil Light marine goo nutes 3 gal. Full spectrum 600 watt led Single spoiled plant in 2x2 tent. 78-85 degrees 50 ish humidity. Now that she's grown a bit the spots are clearer. It's just the tips of the new leaves. Old leaves are fine.