@Sculkur: It looks ok, but I think it is starting to stretch a bit. and do not feed it any more of that plant food from the bottle you showed until the tips of the new leaves are not burned. Adding the nutrients has slightly burned the tips of the leaves. Were is it growing? Have you got more lights? Pre flowers will start showing on the plant at some point, it differs from strain to strain on when this happens....
@Mensa: are the plants in soil or hydro? If soil it may be that the root zone hasn't developed well enough, and if so did you repot them yourself as I remember you saying you were gifted plants from someone to grow?