Please help - What's my plant prob? I'm a beginner

[arastoo777j]

hi, i have one plant around 20 day from seed but i want to know why plant its small
i dont know this plant genetics, plant grow 1 week with cfl and another days with 50watt
led cheapset red/blue ,please help me tnx all...
its too short i dont know why!

 

[arastoo777j]

another pic from grow time ...

 

[arastoo777j]

 

[pufpufpas]

I'm guessing it's the size of the containers. It needs room for roots. It looks good for its age!