Athosanswered grow question 6 years ago Dude, if you are going to grow on coco, a pH meter and EC/PPM meter are a must; be sure to use them. As for your question, as long as your feed lightly, there will be no salt build up. If you want to go ahead anyway, then yes add nutes after the flush, since coco is an inert media and has no nutrients on its own.