Cannot figure this out

Just recently started having issues with this HSC raspberry parfait gal. She's five weeks into flower. Running dwc with GH Maxibloom per the feed chart. Using tap ph'd down to 5.5. No cal or mag since my tap has sufficient amounts of both. This just started a few days ago overnight. My pH had dropped to 4.2 and my ppm was 850. All of my upper sugar leaves look like this and crumble to the touch along the edges. Running 15 Samsung influx strips at 12 inches on an hlg480 dialed down to about 440. I corrected my pH back to 5.5 and lifted the lights to 18 inches yesterday. Any thoughts on this? Is she able to be saved?

Really need a photo of the whole plant for context. I don't see much of anything to fuss about from that photo. Almost reminiscent of light bleaching. But I don't see any leaf curl or anything like that.

Edit: I see some other leaves in the photo now. It's light bleaching. Raise your light homie. LED light bleach strikes again and correct your PH as needed