1st grow........

so i know there are a lot of these threads, im just starting one to hopefully get some advice along my way.
so heres my setup;

2 1/2' x 5' x 7 1/2' grow space covered in mylar
19 " cool tube w/ 6 inch duct
600 watt lumatek digital ballast
" " sunmaster cool deluxe mh and an eye hortilux super hps for flowering
6 inch can fan 440 cfm
2 small fans inside for circ.

the plants are 2 weeks old and look very healthy with tight internode spacing. they are from feminized seeds i personally brought back from amsterdam. 4 total; 3 violator kush from barneys farm, and 1 arjans ultra haze #2 from greenhouse seed co.

temps inside range from low 70's at night to high 70's low 80's during the day. with humidity from 20 - 30 percent.
i plan on giving them nutes in the next week

sensi cal mg mix grow
dutch master grow max

fox farm open sesame
sensi cal mg mix bloom

as soon as i get my camera back in a couple days i will post pics. any advice is much appreciated.