the essence of the question is what actions should be done with the solution when the plant began to feed on fertilizers!!!?

Hi Usually i use this chart for hydro https://percysgrowroom.com/wp-content/uploads/2018/12/PH-and-EC-fluctuations-in-Hydroponics.jpg

Forgot to tell you that yes, if she's drinking water and that happens, you would raise the EC to 1.4 and bring the pH back up to at least 5.8... if she's not drinking, you would have to raise the EC but only to 0.2 lower than it was, so in this instance to 1.0 again bringing the pH back to where it should be...

This is going to depend on whether or not your plant is drinking. If it's drinking (water level going down), you'd need to raise the EC by 0.2.... if it's NOT drinking, you would need to lower the EC by 0.2... I rely on these charts to help me figure out what to do with my DWC (always taking some of it with a grain of salt)... scroll down a ways - there are two charts, one if the plant is drinking and one if it's not drinking.... I "stole" the charts and they are now on my laptop so I can easily access them when I have a question..... https://percysgrowroom.com/ec-and-ph-fluctuations-in-hydroponics/ Good luck...

It depends on the stage of growth, the nutrients being fed, and how the plant looks. Does the plant show any deficiencies? does it have good leaf turgor? Is it happy? Hard to give an answer without the whole picture, but you should always try and keep the PH between 5.5-6.2. In my setup, I would increase the EC to 1.2.5-1.3 and see what it does the next day. Top off the res with less micros (cal-mag) since they are removed slower than N and K. Those PH rise and fall charts on the internet are ok, but they are very basic and don't ask what you are actually feeding and the make up of your solution is very important. Here is a video on how a plant changes it's root zone chemistry by Dr. Daniel Fernandez: www.youtube.com/watch