I'm new to the forum and stumbled on this post researching powdery mildew. So, I thought I'd share my techniques. I've been using Neem and Immunox and it's been great, however I've now got O.G. Kush and have been warned about how susceptible it is to mildew and every other problem. Immunox is not organic so I use it real early on and have made it through with out a mildew problem so far. I take the babies 9 days before I'm going to transplant (4-6inch tall or so) and dip them once every 3 days in a Green Light Neem mix. I like the Green Light Neem because is stays emulsified well allowing for a safe dipping mix that is oil clump free. The 3rd dip I transplant out of the 4in cubes into their final container. I wait about a week to make sure I no pests/diseases before I stop the neem, also letting them recover from the continuous oil coatings (I think it clogs up there stomata a little slowing there growth down about 10-15% from what I've seen). Then I spray well once with Spectracide Immunox Mutli-Purpose Fungicide. The mildew is systemic and the immunox seems to really kill it if there is any there. When you see the powder that means its been living in the plant at least a week. I think that really healthy starts and lots and LOTS of air circulation help tremendously! I'm interested in using sulfur, and I've been told it's the most affective if you're really have an issue with the mildew. I'm also interested in trying pyrethrum bombs for mites the next time I have any. It's hard enough to control the problem let alone totally eradicating them which is the obvious goal. I'm interested learning new techniques and hearing others thoughts, so do share and SMOKE IT UP!!!