12/12 from seed! 4 weeks old.. first gro, feedback?

Ive been using CFLs 12 hrs on 12 hrs off for 4 weeks now & looks like im getting good results.. considering Im usuing MG potting soil plus an organic perlite i ordered online.
Ive read some bad things about MG but I dont see any problems yet? Its growing fast and looks healthy.

Do you think i should add more soil since its not all the way up to the top of the ?

Any feedback is appreciated

your plant looks good bella.. i will typically add soil to a seedling if it stretches out. i will fill at least up to the cotyledon, some times past it... your plant seems to have good lower secondary growth.. unless your plan is to remove this lower growth anyway when purning or lollypoping i'd leave it.. if you transplant into a bigger pot you may want to get to most from the pot and fill it up... just my 2sensi....