1st Time DWC... Plant Death Imminent

I transferred this C99 female from soil to DWC roughly a week ago. For the first few days after transplanting I used only pH adjusted tap water ( I have decent tap water ~25 ppm) and she seemed to be doing fine...

I then added nutrients and additives raising the ppm to 800! This was obviously a bad idea. She suffered some nutrient burn. In response I flushed the system for two days and then replenished to 250 ppm. I thought she would get better but... she stagnated for a few more days before leaves began to droop and crumble as seen in the pictures.

I come to realize that my water level being nearly to the top of the bucket is probably to high. So I dropped my water level to an inch below the net pot. She seems to have worsened since I dropped the water 2 days ago, though not by much.

I am at a loss. My best explanation is that I was drowning her roots for many days and they just need to dry out... is this plausible?

Water temperature: ~72 (drops to low 60s at night)
Ph: Adjust to 5.5; Let rise to 6~6.2 then drop to back 5.5
Relative Humidity: ~40%

I think your on the right track . Water lvl way too high . I only have one bucket going but it's 1/2 inch to 1 inch below the net pot at all times . I have only got some minor bute burn so far . I just did one bucket and the rest soil so i could learn dwc before commiting all my plants to it .

Can anybody out there verify that severe oxygen deprivation can lead to leaves drying out and crumbling? I have scoured the internet looking for a definite answer but have not turned up anything. It just seems counter intuitive to think that overwatering makes a plant dry out and crumble. Thus, I fear the crumbling may be caused by something else.

well plants breath CO2 and dry crumbly leaves may be the lights are too close

"We all learned in grade school that plants "breathe" in Carbon Dioxide and exhale oxygen. However, the thing that wasn't talked about is how the root systems use oxygen!! In hydroponic practice one of the major directives is to supply an oxygenated nutrient to the plat root system. So, in whatever type ofhydroponic system that we use, we need to make sure that the nutrient is properly oxygenated." this is from http://www.weedfarmer.com/cannabis/hydroponicprinciples_guide.php

Yeah I misunderstood just how oxygenated the water needed to be. Initially I filled the water to the top of the bucket as I figured that the air pump oxygenated the water enough to where the roots could be fully submerged at all times.

got pics of the roots

When I transplanted I buried her roots in the hydroton as vertically as I could. So the roots are close to reaching the bottom of the net pot but they have yet to make an appearance on the other side.

im right north of you in seattle. im seeing the same thing and i have the same setup. i think its a phosphorus def caused from low temps. i am having trouble warming things up.

I think your main issue is transplanting from soil to hydro. Next time start your clone or seed in rockwool then go straight into hydroton when they show a little bit of roots. This way the plant will form water roots. You'll see, they're thick. If there is a phosphorus def, you should be able to give them some through your nutrients. but almost all little things can be overcome if caught in time but they have to have a healthy root system