The first 3 or 4 grows I did with Miracle Grow, and yes I had problems like 99% of all nubes when I first started out. Experience is the best teacher. You learn to adapt to whatever soil you happen to be using.
I grew tomatoes for years in Earthboxes and used a potting soil by the name of Sun Gro Metro Mix found at the local nursery. It does't contain any nutes that I can tell from reading the outside of the bag, but it sure grows some nice tomatoes. A couple of summers ago I decided to try to grow cannabis in it and I was pleased with the results. The only thing I do to modify it is to add more perlite. Then feed according to what the plants tell me. I run the used "soil" through the composter then use it again to grow tomatoes and peppers with.
A question I have is- I have never reused the potting mix to grow pot in though tomatoes and such don't seem to mind. Can it be reused and what kind of treatment would it require or do you just dump it and write it down as a growing expence?