Lower Drain EC

use the plant to dictate what you do. When the plant is happy there will be consistency in the runoff... when you find that, that's the 'normal' you want. Don't approach it top-down with some preconceived notion of what the runoff 'should' be without any regard to the plant. The plant can grab molecules selectively, so you could very well lose some concentration depending on how long between fertigations. Not only that, god knows what's going on with microbes and other factors in constant flux. What matters is your growth rate and relative health of the plant. If you are meeting needs and not overfeeding, then you don't get toxicities or deficiencies over time. This is the goal. It's a goldielocks zone, not "more is better." 2.0 was obvioulsy too much. Even 1.6 might show a problem if you give it long enough, or maybe not. I would suggest sticking to one thing at letting it paly out -- adjust as you see a problem. the 2.0 feed might cause some fog of war evaluating 1.6EC going forward. Now, if you see a toxicity you won't be certain if it was the amped up feeding causing it or something that would have occured if given a few more weeks at 1.6EC. in soilless/hydro you want to simply make sure critical levels of each nutrient molecules are available to the roots. Keep it simple and don't play mad scientist too much with the formula.. except to slowly and systematically dial it in to the point of near-flawless plants no matter how many strains you grow at once using the same fertilizer for all. You probably want to drop N 10-20% once vege growth starts to slow down. The plant needs plenty of N even then, but does need a bit less. the exact timing depends on how much n you give previously... it may build up more for you than someone else and require a slightly different approach at a slightly different time.