Light green leaves

Hey, I think you're not letting the rockwool dry enough between each watering. I recommend watering 2-3 times a day in small amounts. Also, try to put something at the bottom so the cube doesn't sit in the runoff water (especially when the pot doesn't allow air to pass through to the bottom). A little tip: hydrogen peroxide helps against root rot, about 3ml per liter of water generally, but you can test with half the dosage to see if the plant likes it or not. Personally, I use it every week at least once to oxygenate my roots. I hope this helps you, and if you run into any issues, feel free to message me privately; I'm happy to help ^^ Happy end-of-year celebrations to you and your family, as well as to all the readers and their families ;)

The main problem here is that you are feeding her from above in this long thin cup full with saturated rockwool while the majority of the roots is laying in a puddle of water at the bottom of this cup. The ratio between water, oxygen and nutrients is off. In this case because of lack of oxygen. Because of the lack of oxygen she can not process the water with nutrition fast enough while she is craving for a lot now trying to make her buds grow as fat as possible. That is why she is using her spare build up nutritions from inside her older leaves and that is why they are fading in colour. All her energy wants to go to the buds at this phase of the grow. The solution is really easy. Move the watering system to the bottom 30% from the cup and she will have enough oxygen at the 70% above to start her little factory working properly and in balance again.