I switched to advanced nutrients in august, I use sensi and iguana, I grow both organically and not. The plants that get fed the sensi grew so much faster and looked healthier. Im still using the iguana for my head stash, and still looking for a great organic nutrient. My plants in flower that have been fed sensi are twice the size than the iguana and look sooo much better. Pretty awesome stuff. As far as the two part system its pretty easy you just put equal amounts of each in at every watering. I always feed half strength with advanced the stuff is strong, so for four gallons of water i use 30 ml of each and 15 of all the additives. I havent pulled down a crop yet with using only advanced but by the looks of it its going to be my best one yet.