So there is a company, Kelp4less, with comparable quality stuff to Advanced Nutrients, and they have seriously awesome prices and free shipping anywhere in the states. The guys over there will work with you to form a nutrient schedule (I love that), and they have suuuuuch good quality. They have...
I found a really good conventional preventative, too - it's MKP (mono potassium Phosphate) and it's a great suppressant of PM. Use it as a foliar spray, it's got a dry analysis of 0-52-34 (no nitrogen). This helps a lot with a PM problem. Hope that helps!