Well, first of all, I'm sure you know by now that this grow is toast. There's no saving it at this point, unless that genius from Colorado can invent a time machine and go back and do about a half dozen things completely differently. You say they vegged for 5 freakin' months? Why? Why did anyone think that was a good idea? I'm surprised they didn't all start to flower just from the stress of vegging that long in 6-inch pots.
I'll tell you what happened. By the time they up-potted, the plants (especially the root systems) were stressed to the breaking point from being packed into those tiny pots for so long. The root balls must have been as hard as rocks, with most of the roots dead and choking each other off. What they should have done was break up the outside edges of the root ball and loosen up the roots when they transplanted, but I'm going to bet they were too dumb to do that. (Although as I think about it, it might not have mattered. After 5 months of vegging in gallon pots, those roots were probably in terrible shape).
But anyway... between that and packing the new coco in as hard as they could (which completely defeats one of the main advantages of growing in coco), the root systems never developed. I'll bet if you pulled one of those plants, they'd come right up out of the pot with a solid 6-inch cube of roots at the bottom. It might have helped to use an enzyme product to break down the dead roots, but they probably didn't do that either.
Because there aren't enough healthy roots to take up nutrients, you're seeing salt buildup. Because the plants probably never did well after transplanting, they probably tried to compensate by overfertilizing (because they did everything else wrong; why not that, too?) That's why you're getting 4000 ppm runoff.
So you've got half-dead root systems packed into the middle of buckets of overpacked, soaking wet coco, with no oxygen or healthy root microbes, surrounded by a toxic brew of heavy fertilizers, and unable to to use any of the nutes because the roots aren't healthy and now they're nute-locked too. This is way too many problems to fix this far into flower. If they'd up-potted sooner (much sooner), broken up the outside of the rootballs, dusted them with Great White , Oregonism, or some similar product as they transplanted, packed the coco more loosely, used an enzyme product regularly, and followed a more intelligent watering and feeding process, they might have gotten a nice crop. But that's way too many things that should have been done differently, and it's too late to go back and do it again. Even flushing isn't going to do any good if the roots are as bad as I think they are; it'll just saturate that overpacked coco and promote rot.
I don't know where you guys live, but if you were close to me, I'd sure love to buy that guy's equipment when he sells it at 10 cents on the dollar next month!
