These plants are overfed. Your plants looked relatively finen 2 weeks ago. Whatever you do, dial back, don't add more.
without better info on the ratios and concentrations of what you fed, it'll be near impossible to diagnose from the current state of the plants. This is more likely an outcome of something(s) being too high than lacking something. I don't see P or K deficiencies, so it's hard to blame that. The symptoms for p and k are fairly distinct, too.
Week 5 - a bit dark
Week 6 - Can see this progressing - darker than week 5
Week 7 - lots of leaf damage that will get worse if you continue to overfeed.
While the exact needs of the plant can be slightly different in vege vs late bloom when vege growth finally stops, the best practice is to maintain a consistent 'critical' level of each nute around the roots. It's not about boosting 1 or 2 like a mad scientist at the "right time." you want 40-60 ppm of P around the roots at all times. studies show boosting beyond that don't add to yield nor impact potency. Same with K.. above a certain level it's just an e-peen and a potential problem if too high. these numbers are for soilless/hydro. Soil is more complicated due to intermediary steps necessary to break down the ingredients of 'soil/organic' fertilizer into something that can actually enter the plant. About 60-70% of P and K enter through what is called "active transport". the plent sends out molecules that can only attach to specific molecules and transports it back into the plant. the plant does not have a CNS, but it reacts in a compartmentalized way. It graps the p and k it needs as it needs it. You simply have to make sure it exists in a proper concentration.. not overpowering each other or other nutrient molecules.
N on the other hand mostly enters the roots through basic diffusion ("mass flow"). They don't all take the same path or proportions in each potential path to enter.
If you keep wanting to feed this way, you will need to go through some trial and error as far as proportions of components in your tea. If you changed anything the last 3-4 weeks, i'd look over those changes and do something different next time, or you'll run into the same problem. Fertilization is about weeks and months compounding, not just what you did last night. Sometimes what you do takes weeks to cause problems. Good thing is that the longer it takes to present itself, the closer you are to doing it correctly.