Seriously nute burned white widows!!!

Hey, guys, I desperately need advise about what to do next. I am currently doing my first ever DWC grow of two White Widows. They were at Week 8 of flowering, but when I started adding Koolbloom, they got nute burn. So I started flushing them with plain ph'd water. Left them alone for a couple of days, tried giving them nutes again, they got burned more. Put them back on flush for several days. They weren't getting any better or worse, so I thought why starve them now? So again I started giving them a low (400 ppm's) dose of nutes. Well this morning, they look WORSE! Before, they just had burned tips and yellow margins on the leaves - today, the leaves look like they're starting to shrivel up! The trichomes on the plants have not developed any further than just looking like little shards of glass with TINY pinheads on them ever since this whole nute burn crap began. What I would like to know from anyone with experience is: What should I do at this point??? Can they recover from the burn and start producing trichomes again, or is it too late? If they're not getting any better and no further trichome development is going to take place, should I just leave them flushing for two weeks and harvest, even though the flowering time was supposed to be ten weeks? Do the two weeks you spend flushing count as "flowering weeks"? Sorry for all the dumb questions, but I have no idea what to do next. I'm not in a hurry - if there's a chance they will get better and crank back up again, I can leave them alone. But, I'm afraid the trics will go downhill like the rest of the plant and I'll end up with nothing. Someone please help. Peace

It would help if you could post a pic and describe the condition of your root zone.

if your in week 8 0f flowering why are you adding nutes? you should be flushing the plant may be going through its natural cycle and dying because its done flowering

I have been flushing them for the last week and a half, but there hasn't been any improvement. What about the fact that the trics never got the big heads on them? I don't know, but the seed company info says 9 - 10 weeks flowering, plus I started counting flowering from start of 12/12- not first pistils (hadn't learned that yet). So, I really thought they still had at least three more weeks to go....

Bugeye, I will post pics later when I can. The roots look fine - no slime, only a little brown stain from the nutes. They're in 5 gal buckets. It may be getting a little on the cool side in the rez with temps around 68F; is that too cold for the roots? I can turn down the ac if I need to. Thanks for your help, dude.