Seedling question

Well just 2 weeks since germination I had 8 out of 12 seeds pop up out of the ground. And I have the plans under a 36W long flouro tube and one of the plants was always taller then the rest and had bigger leaves but the last few days that plant hasn't grown at all and all the other plants are growing past it I raise the light every time one of the plants almost touches the light but all the other plants have grown past it and have now more leaves help??? Did this plant stop growing???

its normal for plants to grow at slightly different rates and very common to see lots of stretching during the first two weeks. However excess stretching often means that the lighting is insufficient or to far away. A long skinny stem also has a harder time keeping itself upright. If it were to bend over and create a crease in the stem it could kill the plant.

Lack of growth is usually not a problem, but it can happen to root bound plants and plants suffering from shock (environmental or nutritional). Not much you can do for shock other than letting the plant rest. With a root bound plant you simply need to transplant to a larger container.