nice too see you got some CO2 in there, but ya id have to agree with buk, dont use that mircale grow crap, it'll only make your pH rise, and its a little early to feed anyways.. im on my first grow as well and i didnt feed until the 4th week. on that 4th week i gave it a pinch of blood meal, lots of nitrogen, a good 12-0-0 mix which is what vegging plants need

if you have the time or enegry, id give it a try