If you growing medium is pre loaded with nutrients, I don't think I would consider additional feedings for at least 2 months, again depending on plant size and size/amount of container/soil. Your plant is still pretty small and has barely touched the nutrients in the soil if it already had nutrients in it. I think you might benefit from stronger light, as your plants look a bit on the small size for their age. Don't get me wrong as some strains take forever to grow, then suddenly grow like, well... weeds! If you don't have any nutrients already in the soil, you could start b giving it a 25% dose of whatever you use, but be careful not to overfeed it, which can damage and stall your growth.