Coco 4 weeks old.
I try to keep PH around 5.8
Currently feeding only base grow feed with some added extra like voodoojuice and silicon.
No calmag is currently fed since having hard water.
Not bugs because no intake from outside.
water every other day
Temp is 70 and RH is 70
Coco should be fed at least daily with your nutrient solution, it's not soil. Your lights are WAY too close for veg, they are showing signs of light stress.
Edit: Also just because you don't have an outside intake to the tent doesn't mean you can't have bugs. I'm not saying you do, but it's not impossible because of the reason you gave though.