Soilless mediums are prone to defs especially in the Zink/Mag and that is why many add lime or CalMag and coco really needs to be of a good quality to get dialed in, it is just like soil with crappy muddy/clay soils that arn't going to do much for MJ, but some just think if it is soil then I can grow. That is not the case as many know by now and it is the same with coco.
If you are serious about growing in coco then you should take the time to look into those links even if it is just for a second IMO. I mean do you want to pull a QP/4 zips off a plant with one month veg without having to grow in hydro? I am getting dialed in to that point and am finding folks who are pulling more than that without fancey proonning techniques or 1000W's, but 600W's.
Some coco porn http://www.icmag.com/ic/showthread.p...highlight=coco


Adieu