Root Rot...!!...Help

I have been combing these forums to try to find some kind of fix for what seems to be a root rot problem im having ...im seeing growth come to a halt and pieces of roots floating in my 5 gallon bubble buckets..also my ph keeps dropping like crazy roots do not look healthy any more kinda brownish looking but no slime...and the buds themselves are shriveling up . Will flora shield help or is it a lost cause ...i have been going through this for the past 2 weeks ..i have changed the nutrients out and have put in plain phd water for a few days but when i added the nutrients back into the mix i got the dropping ph levels...it looks like i may have over done it with Pure Flowers about 3 weeks ago not sure... any sudgestions would be great...!! :(

Can you link some pics?

I'm not a big hydro expert by any stretch, but root rot in DWC is commonly treated with Cannazyme and hydrogen peroxide (H2O2).
Raise your lights right away to keep the plant from losing what little water it can uptake through transpiration.