Stopped growing 4 weeks into 8 week flower, still hasn't started

Here's my grow journal
https://www.rollitup.org/t/my-first-grow-ever-sweet-cheese-dwc-3x3x7.868824/page-2

So I'm thinking it's locked up, what do? If the ph is 5.8 always no matter how many times i water the buckets, does that mean it's nutrient locked?