What medium arw you using? I have alot of experience using alien systems, ive used them all with success and i have a flood and drain running now.
For veg def go with ph perfect micro grow bloom as a base nutrient and you also want great white mycorrhizae either top fed or sprinkled in the media when you transplant. If you are new to hydro i would suggest you use coco coir, a 60/40 mic with clay pebbles as its more forgiving than straight pebbles. Check out my currwnt grow journal as i will be documenting it again along side a hand fed set up to show pros and cons. I will also give feed schedule.