Top dressings in organic grows are great, but it's not a real solution to organic nutrition needs. If you want to grow organically, you can't treat it like a hydro grow; there is no feeding schedule for the plants, you need to think about feeding the soil. If you think that the time it takes to build a proper soil takes too long, then maybe organic gardening isn't for you. Personally I like a hybrid feed of salts and organic amendments for cannabis indoors. Pure organic is best for outdoor gardening IMO.