Root rot or pH imbalance?

so PH is off, but I don't think that's your main problem. It looks like its a hurting unit. Its got burn marks on it and all the new leaves are stressed out and mutating. I think its root system is rotting. It might be easier to take clones of this and start over. My main theory here is the substrate your growing it in just took a turn. Lack of oxygen and aeration. getting compact and needs refreshing. No diary present so hard to see before and after pics but I want to say their might have been signs before it total just shit the bed and they where not recognized. Good Luck!