I also wanted to mention my PureCrop1 applications. I apply in the 3rd and 4th weeks of veg and the 1st week of flowering. Here's the company's description:
"PureCrop1 is a natural plant based biostimulant, insecticide and fungicide made of food grade oils with a zero OSHA rating. Personal Protective Equipment (PPE) is not required and PureCrop1 is safe to use at home around children and pets".
For me, it seems to stimulate the plants own defense, and increases the ability to withstand mites and other critters. I use it at 1 oz. per gallon, on the low end of recommended rates, and only spray when the room is cool, lights out and are given a long period to dry completely. Plants have shown no reaction to the spray and they actually seem healthier in a day or two after the spray.
I haven't had to spray the room with anything else since using it. And I'd say the only negative is it's not cheap, but it does last a good long time. I use about 1/2 gallon to spray down the room, and plants up and down.