If you are growing with coco, or really any soil less medium and not watering to runoff regularly (best to do with every watering) then you are doing it wrong.
There are exceptions to this of course, but if you are using any salt based nutrients in really any medium then you need to water to runoff. Even with light feeding salts will build up in the root zone and cause all sorts of problems.
Study up on calmag and coco and it will all start to make more sense. You are getting lots of good advice here, ya just gotta take it.