Hi there Statman, i dont really like to fertilise autos before end of week 4 , usually it will lead to over fertilisation. if you really want to add something try to add a chelation agent which is something that breaks down the nutrients in the soil for the plant, for example CANNA BOOST, or BIOBIZZ TOPMAX, actually it's also a good idea to add beneficial bacteria which do create a "soil matrix" and stabilises the nutrition of the plant , for example bacillus subtilis and trichoderma harzianum, this will help feed your plant without actually adding nutrients... for now. So i would say wait a bit before feeding, and for sure dont forget cal mag, because cannabis plants always need cal mag even in soil. Hope this helps , growmie ! 🚀