Dude after reading your posts Ive noticed a few things about the advice you've been given, mostly bs. Temp is fine at night 60-70 degrees is the perfect temp , your too hot! Look up online ed rosenthals recommendation on temps, the cooler the bigger yields. You are creating your own problems ,
1. for your space you have too much light = heat. Get a 4 foot VERTICAL parabolic hood and with your space 3-4 will do fine.
Your powdery leaf mold is coming through your ventilation, increase your fan size to about 1650 cfm ( home depot has one at about 50 bucks, look in the roofing department , comes with thermometer also. Put a hepavirus filter on your intake, this will stop your mold. Before flowering get yourself a sulfur burner and burn sulfur for 6 hours then two days later do it again , then spray your plants, that will hold them through flowering. ( it will also kill the spores that are in your room).
get rid of that swamp cooler! Humidity of 60-65 % is FINE.
Your girls are going through too much up down swings reduce the lights increase the vents you will get better results. Also two pounds per fixture can only be done with Plants that produce that much.