try lowering the light, although a 100w should be fine as long as it bright white led not the lower lumin rated ones with an orange/redish light to them. just put your hand underneath the klight bulb and see when it gets too hot after a short time, that will help
can you not leave the light on 24/7? much better squat growth, comes in handy to counteract streach when it comes to flowering.
apart from that nice seedling. you can allways fill more soil in the pot up to the top and water from below, this also stops weeds from coming up and pinching nutes from your baby.