well, while the run-off EC/ppm is good to know, the important part that wasn't mentioned is the EC/ppm of the water that you feed them with..
Without knowing that we can't really say if your plants want more, or less nutrients with each feeding.
Usually it's best to have the same EC in the run-off, as what you're putting in.. if the EC is higher in the run-off, then back a bit off with the nutrients.. if the EC is lower in the run-off then you can increase nutrients in small steps..
happy growing!