Right- and since EC doesn't fall to zero, it doesn't screw with the root's osmotic pressure requirements or starve the plant. I get much better results this way than when I dumped and flushed with fresh water.
DISCLAIMER; I'm talking about SWC, DWC and RDWC only, organics/coco/soil grows are not the same and I'm making no representations about my approach being good or bad for those substrates.