My secret weapon is humanure compost. I realize most folks aren't in a environment where they can do this. But if you have a yard, compost, sans your poop, is easy to do. Yearly additions solved my compaction/drainage issues. If the soil is teeming with bio-activity dry organics are absorbed quicker. The advantage to garden soil grow if you dose ahead of time, no need to fuss during the grow, In the fall all my soil for the grow goes back to the garden bed. A thick layer of compost and a light dusting of high N guano and high P guano, plus a tiny amount of langbeinite is turned in and over wintered. In the spring when soil is thawed I'll mix in a little fish bone meal and a tiny amount of langbeinite as I'm filling the grow pots. I almost never add anything during the grow. My goal is always a strong healthy plant, I know if I do that it will give what I need.