Your seedling looks fine, but definitely take the advice above when you transplant into a larger container. Choosing the right soil is essential for a healthy plant. The roots of a marijuana plant don't like to be kept moist, so proper drainage and aeration of the soil is necessary. Stay away from soils which contain too much clay and add some perlite to your medium to increase the circulation of oxygen throughout the root zone. For better drainage, layer the bottom of your pots with stones, so the soil won't clog the drainage holes. It adds a little weight to your pots, but your plants will appreciate it. I also add sand to my soil mixture as well, to aid in drainage. Mix sand (10%), perlite (20%) and potting soil (70%) and you're golden. Be sure to check the PH balance and nutrient content of the soil you plan to use and stay away from any soil which is clay based and/or contains time-released nutes. Hope this helps. Peace.