Holy fuck, that's about the worst bacteria attack I've seen, I almost threw up
What do the plants look like, they got to be drooping like a weeping willow.
You need to get aggressive to have any chance of saving these plants. Take the netpot out of the lid, trim off all of the roots down to the pot, and soak the pots and roots in a seperate container filled with 6.0 pH water and 1/3 cup of 3% Hydrogen Peroxide per gallon (the stuff you can get at a drug store). See this link, post 8 under over-watering, for an example of soaking:
https://www.rollitup.org/general-marijuana-growing/1469-marijuana-plant-problems-cures.html
While the plants are soaking, thoroughly clean the reservoir with a bleach solution. Clean EVERYTHING. Let everything (except the plants, of course) soak in a bleach solution for about an hour. Get new airstones and tubing. THOROUGHLY rinse everything with fresh water.
When you're ready to put it all back together, mix up a batch of 1/4 strength nutrients with some Superthrive or other root stimulant. Add 1/4 cup per gallon of 3% hydrogen peroxide to this solution. Put the plants back in the reservoir. Add two tablespoons of 3% H2O2 per 5 gallons of water in the reservoir per day until new roots start forming. Pray.
You'll be pushing the limits with the H2O2, but these plants are probably toast anyways.
And fix the reasons this occured in the first place: high water temps, light leaks, poor aeration, etc.!