In 12/12 from seed has a veg. period as the plant build a root system and get ready for flower. I used Mg soil a lot but got tired of bugs. just water with that soil and let it dry out before adding water because you can raise your ph and cause nute lockout, which I learned the hard way. After 3 weeks you can add grow nutes, there should a base grow with the stuff you got if it a bloom nute. Most nute systems have a two part base nutes , plus additives, a grow and a bloom. Veg and flower. Got to go bed. I check in morning and see if you got more question. Check out the 12/12 from seed thread. Later..rw