What you have will work, but it's not "natural" its a synthetic blend. When using it, just remember to wash out the salts in the soil every three to four weeks. If indoors, make sure you have ample wattage and your lights are as close as possible without causing leaf burn. I find I get the best success when I stick to one manufacture and only use their products for that particular grow. Roots will come if the conditions are right. I like to start off in one gallon smart pots. After three weeks the roots will start popping out of the bottom and I'll need to transplant into a bigger container.
Hard to say what the best nutrients are. Each year I like to try out different brands. This year I'm testing Xnutrients. Last year was testing Advanced Nutrients, Fox Farm, and Roots Organic on different plants. A few years ago I used Alaska Fish Emulsions and before that I used Kellogg's product. Out of all the grows I've had so far, I did the best with Alaska's fish emulsions (5-1-1) and their bloom formula (0-10-10). Dyna and Canna are on my list of nutrients that I'd like to eventually try. I'd even like to get my hands on some Jacks 20-20-20 All Purpose Fertilizer.
There is disagreement about what's the perfect NPK. I generally favor a 3-1-2 ratio during veg and a 1-2-2 formula during flower. But honestly, when I've done 5-5-5 or similar ratios, I still get great results, so who knows. The one thing I've notice beyond doubt is that lights matter and bigger containers support bigger plants.
