Transplant shock

Had seedlings in aeroponic system 3 weeks. Well when was away power tripped and was without proper air water. Algae was built up and roots no longer white, but yellowish brown. Did a root flush and cleaned entire system. Had some wilting and blackened leaf which I topped. Did transplant in coco after 5 days to start my veg cycle(roots had regained color and wilting was gone)and just crashed so hard. Not even 30 min after transplant clear shock. Whole plants just slumped like a drunk hobo. RN using 4-0-1 npk at 1/3 normal dose with 1 tsp phosphor magnesium per 4 Liter. EC is 1.02 PH stays at 5.8. For clones and seedlings I use 200W FS lights. Only had this happen about 3 times in 22 years. So any tips appreciated. Normally I just let em crash and restart, but got some Purple Queen, I rather not reorder. Has always been a stingy plant to work with.

Got no clue or experience with your system, but my reading makes me question the

New? used? Flushed? pre-wet?
Sorry, I don’t use coco, either.
My problems come from PH/PPM pen issues, overwatering, or my memory.
Seriously I have lost 2 tent grows and 4-giant sunflower plants from using dehumidifier sourced water (2-new dehumidifiers, different models, both source toxic 4.0 water).
Best wishes for solving the issue.