I know I have powdery mildew and I have used baking soda before to get rid of it. The problem is the last time I used it I almost killed 3 of my plants. I believe I mixed it to strong. Do any of you know the proper mix ratio of baking soda to water? How long should I leave the bs/water mix on before rinsing it off the plants? How often should I repeat the remedy? Is there another cheap remedy? What is the cheapest way to lower humidity in a grow room?