npk? and check your ingredients, hopefully its not too hot for a seedling. id suggest fox farms light warrior. also, i compost the soil under a huge tree that covers my back yard, leaves have composted on this soil for years so its really rich. i add this to a tray and putting it beside your kitchen widow would also be good to throw in egg shells, old fruit, and also give it some water if it needs some moisture.
and hydro is the best way to grow, but for the people that cant check their grows often and cant afford high tech hydro systems that can add nutes or adjust pH automatically if they arent there to do it themselves, i dont prefer it. if you can, grow a bunch outside and just let them run until august, if your leaving for a few days give it a good water and check the forecast to see if its gonna rain, mother nature can usually take better care of plants than any of us.