Quick One stealth grow

Easy week, just watching her grow. Giving her more and more nutes. The last couple of days she has started to show somewhat of a nitrogen deficiency, with yellowing old leaves and lime colored top leaves... Not sure whether it’s just the normal dying of old leaves towards the end of flowering, or maybe I have a slight pH -problem. All the Biobizz nutes are fairly acidic, and now that I give higher doses, the pH of my water mixed with nutes goes down to 5.5. Maybe I will just give her water without nutes for a couple of days (my tap water ph is close to 8 pH). Many people seem to suggest using pH up is unnecessary, but I’ll see what I end up doing.