Deficiencia o exeso de K?

This is a classic phosphorus deficiency... your nutes aren't providing enough of this essential component - nor are they providing, imho, enough potassium... In flower, the ratio of NPK should be 1-2-3 so twice the amount of P than N and 3x the amount of K as N... but be careful as plants in flower do not need a lot of N... they need SOME, but not a LOT. The good news here is that your pH is in a perfect spot for the absorption of these nutes... she just wants/needs more... so consider adding a PK booster such as General Hydroponics KoolBloom liquid (NPK 0-10-10) to your nute solution. I generally start this about week 2 or 3 of flower then then switch to the KoolBloom dry formula (NPK 2-45-28) for the last couple of weeks before harvest. I think she would respond quickly and happily to this... but the damaged leaves will not repair themselves, so don't expect that. Good luck!