Its a combination of potassium and boroN deficiency, the LEDs ain't helping either. Its sapping the energy the plant hasn't got the fuel to keep up with. its affecting the biggest as they demand more feed as they are bigger and closer to the light by a few inches? if they are closer led par would increase. This Would stem from a pH issue or simply underfeeding the bigger girls. Check your hydro system, flush with pH and nutrient solution. Increase feed. Also increase light off temp, this can affect uptake of nutrients.