Leafs on top turning slightly yellow and getting black spots

yee black doesn't look good, bacterial or fungal, most likely from a medium retaining too much moisture over a period of time for the environment it finds itself. Careful with flushing too to reset ph or lower ec as you will leech nitrogen, particularly in its nitrate form (NO3-), leaches into water when excess water moves through the soil. Other forms of nitrogen, such as ammonium (NH4+), generally do not leach as readily because they are attached to the soil particles and resist movement with water. If ammonium exceeds over 20% of total Nitrogen you are headed for trouble. Never trusted those fabric pots tbh, I always found them to be way less airy, than I need them to be, moisture would sit too long. Not sure there is a solution to fix it. In future look to prevent the conditions from ever arising in future, airpots helped, good advice would be to learn as much as you can with regard to transpiration, respiration, perspiration, evaporation and evapotranspiration. By creating a cycle that ensure there is little to no moisture left on a daily basis is key to preventing bacteria of fungi the opportunity to multiply. Bacteria and fungus are like fire they have all they need to grow except time. Never give them time to even have a chance to stagnate in the medium. Temperatures above 78f bacteria multiplies like 10x rate. Plants looked bloody amazing too, sucks! Hope she recovers.