You probably won't need more intake/exhaust. In the future you always have the option, but
78 is a great temp to be at. Yea humidity is low, but when they grow, and you are watering
them more and more, they will be sweating more and more, humidity will naturally go up in your space.
Yea, they are looking good, growing little by little, You're in the miracle grow, so I'm sure there are some
time releaseed nutes in there, and they will be able to be fed for the first 2 weeks or so, I wouldn't add nutes
Until after transplanting. Unless they begin to show signs of deficiency, in which case, just post pics
and we can tell ya the problem.