This week I moved them to a 15L pot, the final one.
I added Bio Grow but did not stop using root juice because I transplanted them.
Purple Punch II was the one that was struggling in the beginning but I believe she will keep up with the others.
@PrinceBoateng, LST means Low Stress Training.
It's a training method where you bend the plant so the lower branches get more light, this will make the plant grow with an even canopy which makes you have multiple main buds instead of just one. :D