great info all around...flushing is to remove unwanted elemental salts from your plant!
flushing in a unit like yours has more to do with the plant than the bucket...you merely replace your nutes with water. (once at transition...once before harvest)
If pure water...proceed for 1 week...If water w/florakleen added...proceed 3 days...(note: florakleen is the fastest flushing agent on the market...there are others...such as clearex, and final phase, but florakleen is also what I use to kleen my hydroton between grows)

Get gh 3-part...best price proven great results, and works great with just about all additives.

you know that bud blood only get's used 1st week after transition...Good luck