mag and cal as of now, 5th pic tells it all.
are you using any ro water or calmag supplement?
here's what i would recommend you do, either drop the ro water (especially if you tap water ppms aren't that high), and add some cal mag to your nute regime. after you make your mix adjust ph to 6.3-6.4 and i'll guarantee that your issue stops.
i am telling you from experience, because i too had the same issues and stopped listening to what others heard and went with common sense. fact, ph fluctuates back and forth and if you're ph'ing at 5.8 and your ph fluctuates -1 or -2 you're going to lock out a lot of key elements.
if you google or visit most of these sites, people will tell you that coco stores or builds up a lot of salt and this is the main reason why.
after researching, trail and error, and talking to a lot of experience growers, ph'ing your mix that low in any soilless medium is going to cause nothing but problems. why you think there are so many help me threads here? i hate to say it, but this site spreads nothing but misleading info.
take what you want from it, the decision is on you. if need be, i'll post some pics of my first shot a coco (which is my current run) and prove to you what i know as oppose to what someone heard and puts down in a post.
