I have been using the Jacks Classic 20-20-20 for a while now, and have been pretty happy with the results. @dogster recommended the Jacks Professional 20-20-20 a few months ago with the promise that there would be no need to PH or anything, and I was more than willing to give it a try.
I called JR Peters and asked what the difference between the classic and professional was, the guy on the other end of the line said the only difference was that the classic was a finer powder, he is wrong.
This is the professional, notice the magnesium?
Here is the classic, no magnesium, and it’s starting to show in flower.
Rather than buy a 25 lb bag of professional, I am going to try their 10-30-20 blossom booster in flower, and see how that works.
Ordered it today. I will let everyone know how it goes over the next few weeks.