thats good..now when i put a seed to germinate in the 18 l pot i usually fill the pot with 70% mixed soil..i put the light high up to bring them up .constant light..then when they sprout as they go growing up i do fill the rest of the pot with mixed soil..thats because i want to create bigger roots all that stem comming up will get roots because u filled it with soil ..thats only when u want big stems haha..the biogger the roots the bigger the stems the bigger the plant and ofcourse together with good nutes program a bigger yield