I agree with others saying it’s your water temperature.
I used to run nothing but dwc, I know your not running dwc but it doesn’t matter.
You can try pool shock, bleach, Hydroguard, Great white, etc… but I doubt it will help.
It didn’t help my issues with root rot.
It was even in my areo cloner as well which is a similar setup to yours.
What are the daytime and nighttime temperatures in your room?
Let us know if you find a fix. I loved doing individual bucket dwc.
Hydroguard and bennies were a complete waste of time and money for me. Sterile with calcium hypochlorite has kept my plants alive and happy for 5ish years so far.
It may be a temp issue I expected it to be cooler but it is just under room temp. I also shot a photo of the system under the plastic for anyone wondering what it looks like.
What looks like white foam on the water or sides is fresh water splattered the system just ran.
Res return works on gravity, no option for moving it as out side this room is the veg room. (Still warm)
I want to thank everyone for their input. Please dont stop all ideas are welcome, i am going to have to try to chill the water some, does anyone know the fine line temp on this. Cause when you water soil you literally want the water up to room temp so as to not shock the roots, how cold do you try to get your res water?
As a temporary fix, you could freeze bottles of water and put those in your reservoir.
But it gets old real quick constantly cycling in new frozen bottles. I put some pennies in my bottles to keep them from floating.
Your setup looks similar to a recirculating dwc system. I think your best solution would be an inline water chiller. Or if at all possible move the main res to a cooler room.
Hell I used a wort chiller coil at one time to combat the root rot. It worked well for a small scale grow.
I ultimately gave up on dwc. The thought of relying on a water chiller for my whole garden turned me off. Google says rdwc ideal water temp is 64-72. I would aim for 65 ish and see what happens.
You have to get creative sometimes to find solutions.
Nice!
I probably wasn’t using enough pool shock.
May I ask how much you typically use?
I agree, I think sterile is better than the bennies.
@Rubixone if you use pool shock, do NOT store it on or near metal objects. It will rust the hell out of them in no time!
it’s not exactly as if that’s directly obvious 
no need to get so defensive
Said I appreciate the idea. Apologies if you took it any other way.
I was making concentrate jugs for awhile. Something like 2 grams into a gallon, and then can dose something like 2-3ml/gallon of res water. I’ve since gotten lazy tho, I make 5 gallons of nutrient water at a time and for the last year or so I’ve just been throwing a pinch of the calcium hypochlorite in there when I’m done mixing it all up. That and a bit of Drip Clean and I haven’t had any build up or anything. May need to add more calhypo after 3-4 days if it’s still sitting out and/or running a pump in it tho. Bit overkill but the plants don’t seem to mind any if at all.
100% I keep mine in pint mason jar.
ALSO, not all pool shock is made the same! Check the labels. Only some are pure calcium hypochlorite, the others are various other mixes, all labeled just ‘pool shock’
Ever seen hlvd in hydro? Does it look like root rot? I trimmed all these with the same scissors, a few days back, before this, i also switched to hps lights for winter and flowering as i prefer their yield and heat out put. Im in a colder area. But I suspect hlvd its hard to say, is it some funky genetics or is it hlvd playing games on leafs other wise looking heathy, one plant with kind of horizontal branches but i crop the piss out of my plants too. Hlvd is the one thing i have never had, but after an extremely low yeald this summer, from some clones i took in locally i think i may have to also reassess things. As i started new plants i thought it was the genetics. Id give 20k a year to be young again and have the energy for this. The other two are just bushing further no more height under hps change out, are they maybe stunting, my adhd mind just runs with possibilities as to what this was, if it isnt the water.
I mean… if the plant has hlvd, it’s not going to be as resilient to issues as a non-infected plant, but it’s not why the plant would get brown/slimy/smelly roots. If the res smells like anything other than fresh rain and vegetables, if it smells bad/foul/feet/etc, it’s bad bacteria in the water.
Another option instead of adding beneficial bacteria or going sterile is, adding an RO system.
How would you add an ro, they are very slow, or at least mine is in the house. My water is pulled from ro mainly, otherwise distilled.
70°f is nowhere near too hot for res water. I’ve never used a chiller, etc in a reservoir in my life, and I’ve had tents get well into the 90s. My res water sits at around 85°f and I pull 10-12oz monsters OTR.
With the pool shock, my res has ranged from 74 to 64 and the plants have received water at those temps, and the water and plants have been fine and happy with no algae or root issues.
As far as amounts of pool shock, with 52% I’ve seen 1g/gal, so the 73% I run at .75g/gal and that’s been fine. I have an ORP sensor and I add more when the ORP seems low. It’s very precise. 
haven’t read the entire thread but for the op… get some more oxygen in there. it’s impossible to have something rot when you have lots of oxygen involved. algae grows very slowly under the presence of oxygen… however without oxygen it flourishes [ uses sunlight to create energy via photosynthesis ].
i don’t see any aeration and i can tell you with 100% certainty your problem is ‘no dissolved oxygen’. DWC suffers extremely from no oxygen and aeroponics needs air otherwise it’s just a over-complicated dutch bucket / NFT system.
rot comes from wet anaerobic environments. rot can’t happen if you have enough oxygen. fix the oxygen and your plants will be happy.
edit the telltale sign [ to me ] is your first photo. all of the ‘outside growth’ being furthest from the stem is super wilted. wilt is caused by either too much water or too little. if you look at the central part of the stem where the newest growth is… it looks ok. this is how you know you’re basically drowning your plant. the leaves become water logged and that’s why they wilt.
@crunkyeah I plan on adding an air stone today, as other have suggested it as well an i have a few air pump and stones laying around from previous dwc. Ty I appreciate the in put.
In my experience, a light leak can cause root rot.
The light causes algae, which eats up oxygen in the water and can cause root rot to happen. Especially if there are other factors too (temps, non-treated water, etc.).
Once you have that root rot fungi in your system it can be tough to get rid of without breaking the system down and disinfecting everything, and maybe replacing air stones (unless you disinfect them well).
I have tried to continue grows after getting root rot with mixed results. I have been able to finish a flower run numerous times. But if it happens while I’m still in veg I usually just start over.
A reservoir chiller and either a live or sterile res are your best defense. That and cleanliness.
For a live res, southern AG bio friendly fungicide has worked well for me.
I’ve heard lots of people have success with that “Heisenberg tea”. I think I tried it once many years ago but can’t remember.
For a sterile res there are lots of options.
My favorite product by far was Dutch Masters Zone. But they don’t make it anymore, or at least I can’t find it.
Hypochlorous acid works well.
Pool shock (in very low doses) is supposed to work well too but I haven’t done it myself.
I did bleach and manually scrub the system after I caught the problem both times, second time i replaced the buckets, and built a fresh system to try and be sterilized. Going to sterilize the system tomorrow again. The roots look great on the two remaining plants. They are still in veg.
I didn’t realize this was a recurring issue. Guess I should have read the whole thread! lol
So yeah you obviously have an issue if you sterilized and started fresh and it still came back.
Or did you put the same plants (from the system that had root rot) back into the new system?
More air stones and a stronger air pump is a good place to start.
Also, I really like to run something called “physan 20” in my system after issues with any type of root rot or other fungi/bacteria. It’s a really effective disinfectant for that type of stuff.
I had algae on all three plants roots and hand washed them, same plants. Two survived, it was the algae on the roots that killed them i have to assume that caused the rot, and the other two must have just survived. I have already added a 4 or 5 in long air stone. But the roots did look clean when i was done,
