Do not use a continuous release fertilizer. They are not that good and can cause the soil to have a salt build up. Use solutions that disolve in water. Also, I would seriously suggest not using any ferts during the first month of a plants life. Cannabis can usually live the first month, month and a half on the nutrients in the soil. If you have enough addivitives in your soil then you may never have to use ferts.

Happy Toking :rasta: