It might be a pain and I know you said before you were restricted in opening the doors fully, but if you can then try and give the res etc a proper clean, getting everything out and using some mild bleach solution. Do another DM dip for the roots (soak them for a good 10-20 minutes) and keep running it at 6ml / 10l.
The thing we need to work out now is what's causing the root rot. There's one fundamental cause (not enough oxygen at the roots) and three possible things that contribute to this (or a combination of these):
- res temps too high reducing the nutrient solution's ability to hold O2 (and warmer temps also encourage bacterial growth, though the zone will prevent this)
- not enough enough O2 in the solution generally (do you have an air stone and pump so loads of O2 is getting in?)
- too much water / nutes to the root ball (shutting out the O2 as the roots and medium get over-saturated)
Looking at your system, are those drip feeds, and if so do you still have them running? I ran a similar system and found later on in the grow when I was running the top feeds things got a bit unhealthy because the top of the root ball gets very dense and you don't get enough O2 to it if the top feeds are running. Once the roots are in the res you don't need the top feeds and the plants much prefer it when the net pot isn't being continually bathed. The roots do fine being permanently submerged in aerated nutrient solution, and if you have an air stone the bubbles keep the net pot and root ball moist, but the top feed I've found overkills it and rot can set in at the dense top of the roots and water line, and then spread. So some other suggestions you could try after you've given things a clean again:
- turn off the top feeds, they're not needed now
- if you haven't already then get an air pump and put an air stone in the res (though I'm guessing your system has one of these anyway. You could put a second in if you can)
- if the res temps are getting too hot then try keeping them cool using bottles of frozen water
You're very late in flower now and probably not far off flush so to an extent it's about containment and preventing it from progressing, don't expect miracles. I wouldn't increase the nutes until the roots are recovering - I think the deficiency is a symptom because the roots can't take up what they need. At this stage I think it's about containing the rot and solving the root cause, run the nutes at the concentration they are (possibly even consider lowering the ppms slightly until the roots show sign signs of recovery). Hopefully things will recover a bit and she can take up some of what she needs before you flush. Shit time to happen though in terms of time to recover, but good in the sense it's late in the grow so you'll get some smoke and you can fix the cause ready for the next grow
I'm pulling up a chair even if I'm late for the show.
