The Botanicare feed schedule for soil gardens is way off. If you follow it to a T you will wind up with 2000 ppm. If you half it you're at 1000 ppm. I just put out this fire with a friend who was using that schedule and burned everything. Mix up your solution at 1/4 power and check your ppm. If your soil is hot then you can see how if you 1/2 it then the active soil will raise that number. I would take the ppm of the runoff after 20% flushes through. Write that number down. Take the ppm of your water. Now add those together and then mix your nutes to be sure that you don't get past 1100. I hope that was clear if not I will re write. Good Luck!
Oh and check out WeedHound's botanicare sched!