Hey green, so flushing isnt always a must, i know many people dont, but typically theyre growing organic. I think if your feeding schedule is pretty low you're already eliminating a lot of potential build up. I think flushing between 3-7 days is a common range. Either you can slowly eliminate the nutrients to where you're left just with the bud candy and then flush or continue the week and then flush it all. In my opinion with dwc youll only need a few days flushing as you dont have soil etc to worry about, they tend to hold much more than a dwc grow.
Happy harvesting, your buds look great, love the white color. ✌️