Coco coir buffering

My understanding is that it’s just interacting with the coco in the way you want it to.. that coco will naturally suck up some of the cal and mag and maybe some micros.. so the solution is losing it’s available cal and mag as it’s attracted to the coco.. now when you feed, the coco won’t suck up that cal and mag.. your roots will. I’ve never actually taken a before and after when I buffer, but that’s what I’d be looking for is a dropping EC/PPM