I`m over at hearts place out in the swamp, testing his stuff and fighting gators.
I think you should flush again, and add 1 tspn hydrogen peroxide per gallon for the final flush
when you mix the nutes for refilling of the res. just use the one kind, do not mix em together.
the hydrogen peroxide flush should help clean the roots. hopefully the roots werent burned beyond repair.
let me know what happens and i will be back home next week.

hope this helps
i will check back tomorrow on hearts pc
peace
and
grass