Feeding EC 3.2. Runoff EC is 2.3 HOW?!?

EC measure electrical current and is only moderately correlated to concentration in this context. Microbes could be changing composition of the solution present in the medium. The medium could be releasing things from cation exchange sites. Different constitution, even if same overall concentration of solutes, could give a different EC, too. Judge leaves for that stuff... if they are progressing in either direction you know there's an excess or deficiency. Overall concentration is good to know but not too informative for this. Tells nothing of ratio of nutrients which is equally important to properly assessing it. Look up how many different conversion factors there are for eC to ppm.. LOL... should tell you enough about the precision of such a calculation. EC is important too.. the plant will be operate better avoiding extremes. Soil contexts are naturally higher than soilless/hydro contexts.

Well how much runoff are u feeding too? If just a lil runoff it pretty normal for it to be a bit little lower and you'll see it bump up when you push a lil more runoff, if that is the case your initial reading for sure is not the root zone ec. If it's Coco could be absorbing carions, or u could have channeling going on and if that's the case can't trust that runoff ec is the actual root zone ec. Doubt you need to bump feed ec anymore and if you actually do I'd just feed to a lil less runoff and let the ec stack instead of raising the initial ec, but that's just my 2 cents. Sure someone will tell you what your issue definitely is and exactly how to fix it anyways ;p