When I first started out I was using MG soil and when I moved up to Roots Organics 707 mix I saw a huge difference. I am just about to wrap up my first DWC hydro grow though and I think soil is a thing of the pst for me. DWC is awesome!!!
Im not sure how youve been using it for 40 years because it was just introduced in 1997.
Taken directly from the JR Peters website: "Introduced in 1997, the Jack's Classic® water-soluble plant foods are the finest products we have ever made for the home grower."
I use HPS only due to the fact that the lumen output is much higher. MH is the ideal spectrum for veg but I feel the lumen output benefits growth more than the ideal spectrum.