Medicanna answered grow question 2 seconds ago
Hey man, it's hard to judge without any other background info. We all can just guess. When you apply fertilizer, keep in mind that you won't see improvements immediately, leaves that turned yellow will stay yellow, leaves that have been damaged will stay damaged. Its the new growth that has to be good looking and healthy. Also you can tell the fertilizing worked if the damage is not progressing as fast or not at all (best case).
I bet you are using synthetic nutrients. If that is the case, which line are you using and have you checked the pH of the solution you are watering with? Should be somewhere between 6.0 - 7.0 for a soil grown plant.
Usually yellowing leaves starting from the bottom and going up is a nitrogen deficiency but I would NOT just add more N because of that. Like I said, its hard to tell exactly. Most of the times, we think its not enough of a certain nutrient and by adding more we lock out the other ones which results in deficiencies caused by toxicities. Damn does this even make sense? :D
As for your leaves on top, it looks a lot like too much of something. Only thing I can think of would be a slight phosphorous toxicity? Nitrogen wouldnt make any sense with the yellow leaves and / or without the typical leaf clawing. Potassium can be ruled out because the lower leaves show a light deficiency.
Also, Picture #1 bottom right looks very much like a early - mid stage Potassium deficiency (burning edges and turning yellow from outside to inside)
But yeah if it's getting really bad and you cant figure out exactly what it is, I recommend a good ol' flush with distilled water pH'd to 6.5, let it dry and then apply a light / normal, pH 6.5 nutrient solution for the next watering.
Plant is looking nice otherwise, I really hope I didnt confuse you too much, just tryin to help; good luck and keep it up man, bless up!