There are 3 main nutrients for plant growth and several micronutrients. If you look at the label on fertilizers, it gives 3 numbers like 15-15-15, and that's Nitrogen(N)-Phosphorous(P)-Potassium(K). Yes bloom formulas have a higher P & K like 5-15-12, and there are bloom "additives" that have even higher ones like 0-40-30 but you need to be careful with those and only use them in small doses very seldomly or your plant will have severe problems. I like Fox Farms fertilizers and additives because they are specifically made for cannabis and they have an idiot-proof feeding schedule on their website so anyone really can use them with good results. The soluble additives are pretty expensive though since they aren't necessary, but they will help you maximize your crop.