seeds are quite old which is why i think they are growing slow but maybe its too much light, they are under 2 mars hydro 300s in a 3x3 and arent stretching at all 2 weeks old now
They are still young plants, if they are dead center under the lights and the lights are too close to the plants it will stunt the growth. Try moving them to the edge of the light or raising the lights up a couple inches.