When is the best time to flush and how long would ...

Always go by your trichome color. I would start checking the trichomes when about 50% of the white pistils have dried and turned orange with a 40x led lighted jewelers loupe(Amazon.com) When you see more cloudy trichome than clear I would get ready to start your flush some growers will push and wait until they see mostly cloudy. This should leave you a 10 to 14 day period to flush before harvest. Most growers will harvest with mostly cloudy/milky and 5% to 30% amber trichomes depending on what type of high you like. The more amber the more of a body high. 👍