So I finally got some relatively decent PH meter and it turns out I screwed up.

So I've slept on it and now I think low pH may be due to the nutrient buildup in the soil, since I was pretty generous with fertilizer, plus the high pH of the solution would cause lockout. Am I thinking correct? In that case would it be best to just give her pure water from now on? I wanted to start flushing anyway sometime next week, so maybe I should stop the nutes altogether until harvest? I don't think she has more than 3 weeks before being ready for harvest.

@NobodysBuds Thx for the reply. What confuses me is why would the soil have 5,5 PH if it was watered with 8 PH for 6 weeks? How can I raise the PH then? BTW I'm using biobizz allmix soil, which supposedly adjusts the PH itself, but why would it adjust itself so low? Is it possible that alkaline solution would cause the microbes to adjust it even more towards acidic side? The soil is supposed to be 6,3 out of the bag, so it doesn't make sense to me. Also what do you mean by leaves clawing? Some leaves are bent because they were against tent's wall. Or do you mean the burnt tips? To me it looks like it has calcium/magnesium deficiency (the brown spots + low PH) I added some calmag, but I don't think it'll work anyway 'cause the low PH causes Ca/Mg intake lockout.

if pH changes from runoff, it has to do with wht is in the substrate already... Either nutes that were not absorbed and evaporation increased pH by reducing water volume AND/OR microbes are producing an acidic environment. If it dropped to 5,8, expect it to be a bit further... small dip, so not too far. You are getting an average of what you added with what was there, so it's probably a bit lower than 5.8, but not an extreme amount. There is a little clawing on some leves -- indicates overfed. It's not extreme, so minor adjustment needed, which may also help on the pH. It's important you get your pH consistent before trying to fiddle too much with pH. Raising it a bit may solve all problems. It takes time to see the degradation stop and start to heal. It may have been a good thing you were adding ~8pH, because you likely need to raise substrate pH a bit. i'd wager if you bring it up to ~6.5-6.8 you'll see everything improve. This is the the right range for a soil grow.

BTW it's the same leaf one day apart.