I'm a massive fan of the botanicare line of products. You can find a sticky in the hydro section, but the formulas can be used for soil as well. It's mainly organic, but not 100%. Your going to get many answers to this, but i would suggest picking one company and sticking with there line of products throughout the grow. If you do plan on using botanicare just a note to use 1/4 strength the first feed, and bump it up a little each feeding until u notice slight burns and back off. There line of products are rather strong and the recommended dosages are usually to strong.