Nutrient strength & EC testing
I can't locate where I read this but the moment I did it seemed entirely logical
Basically you measure the EC one day, come back in a day or two and if the EC level has dropped your nutrient strength is too low (the plants have used more nutrients than water) and if its gone up the nutrient strength is too strong.
One would think you could find the exact amount of nutrient strength the plants want this way and use it, topping up as required (and recycling as neccesary).
But this gets me thinking, assuming the nutrient is chemically balanced exactly as the plant would want it, is this all really optimal for growth? Should their be excess nutrients in the solution? Any ideas?