Is your profile picture motivation dude,look's like it.
Looks very very nice indeed,are you feeding through the coco or via the root system,What i mean by that is i use auto pot's,so the only time nutrients go through the coco is when the plant's are very young clone's for about a week till the root system hit the bottom of the pot's.
Once the root's reach the pot bottom's then the roots are just in a small amount of feed with a air ring bubbling the stuff,When using a method like this then i say a 7 day flush is fine,If you are feeding the coco then i would go with 14 day flush,for the reason that the coco will hold nutrients,