Yellow leaves (lower part of the plant)

A little bit more info... the good thing is that I have two plants: the first one (the one that appear in the pictures, on the black pot) being fed with nutrients and the second one 100% natural (just watered with tap water). So, after comparing both, this is what could be happening: the plant without nutrients looks healthier (just with two or three leaves turning yellow, which is for sure the starting of a nitrogen deficiency due to the fact that it is flowering and I am not adding any extra nutrients). The other plant (the one with nutrients, in the black pot) also has a little nitrogen deficiency, but the main problem is overfertiliziation: appart of the yellow leaves, it also presents browning leaf tips and margins, very slow growth, etc. since last Thursday (the day I fed it last time) What do you guys think? Just in case, I won't add any nutrients during this week, just water, to see if the situation gets better.

I dont see a detailed log on how much your feeding your plants.. But it could be the start of Nitrogen Deficiency. Here's a helpful link on that subject! https://www.growweedeasy.com/cannabis-plant-problems/nitrogen-deficiency Cheers and happy Growing!