There are many grow-reports available (here & elsewhere) of EC risings, plus this chart
View attachment 4643932
actually gives evidence of a rising EC. ("plant is drinking more than eating")
This is the result of selective ionic transport - we had that discussion prior - remember. Ion-channels, ion-pumps & carriers are actively transporting nute molecules into the plant (and back out of it)
Secondly, the way how roots properly work can be re-read in any basic book on plant physiology. It's not like we need to speculate about these things... and I would be very happy to take a few shots from my college-books but they're in german so you won't be able to decypher it...
but maybe give this guide some time?:
The big read. Integral Hydroponics Evolution @ 2016. 100 A4 pages on hydroponic nutrient science. Undoubtedly the most culturally appropriate and informative material about hydroponic nutrient science…
medteknutrients.com.au
it's really informative & on spot
Greetings