Big deal? Feeding 2L every 2nd day with tab water...

From diary photos your plant is too dark - aka overfed. I would slow down personally. Dark leaves are not so efficient, plus overfed plants can go into stagnation and wont develop so well vs better feed ratio ones. Not a tragedy, far from it. Autos need way less food, theirs flowering cycle ussually is faster, so it will be hard to get fade and good taste with high feeding doses. I would personally give few waterings just plain phed water when needed and i would roll down that pot excess like a sock for better air movement under canopy and root zone.