From what I understand coco has no nutrients and should be feeding from the start. IMO easiest thing for you to do now is transplant them into that happy frog. Or start over from scratch if they're autos..
if so, where is it. Is the hot air at the bottom of the tent sucking into the tent, or blowing out of the tent? Check with one square of toilet paper to see where there is suck and where there is blow..