I'm planning my next grow and have been doing it the same way for a long time. Pro Mix and Miracle Gro. I've been doing it that way for decades. But I want to shift gears this year in a number of ways. When I was an avid outside gardener I had spectacular results with both cow and horse manure. I'm thinking about looking to make a soil mix with organic fertilizer that I never need to add anything more from start to finish except water. Is there an organic substance I could mix with my Pro Mix to make that happpen? I'm hoping the solution is simple and doesn't require complicated measures of various substances. I'm willing to go that route if necessary but I don't want to. The simpler it is, the less likely I'll mess it up.