NL, Moby Dick, GG #4 Auto - First Grow

All the girls survived through first week and this simple fact made me happy! I decided to feed them in this second week. Chose Biobizz, since it's my first grow and I want to avoid overfert burns. I'm watering my girls only once a week, because I'm using big pots and had no problems until now. Since day 8 I'm moving them outside to sunbath during daytime (7 -8 hrs of direct sunlight) and apparently they are enjoying it. I added some protection inside the pots from the heat and sunlight. My only concern is the humidity levels where I live, the climate is arid and humidity around 11-25% GG #4 is the biggest one, followed by Moby Dick and NL is the smallest. I don't know if this is normal, because the water and fert amounts are the same... Update: Day 13 - last day of the second week, no problems so far. Added some nutes on day 12, bio grow - 1ml/l. I haven't decided yet if I'm going to top, fim, or keep my girls grow naturally.