Well I can say you would benefit greatly from an RO system. I highly recommend this one for budget reasons and for small grows -
https://www.amazon.com/3-Stage-Port..._5?keywords=geekpure+RO&qid=1687409269&sr=8-5
When doing Hydro it's always best to start out with clean RO water. My hydro systems are custom built NFT style setups. As some of you may or may not know, NFT is highly prone to light leaks and resulting in root rot.
First might want to make sure your whole hydro system is well sealed from light. You don't want any light getting into the reservoir or the root zone, this is what generally causes root rot to start.
Second, since I use NFT style, I generally run a sterile system.
Hydroguard only works to a point. So I put bleach in my NFT reservoirs. Use Clorox disinfecting bleach (NOT the splash-less crap, make SURE it's "disinfecting" bleach whatever brand you buy). The stuff I use is 7.5% Sodium Hypochlorite.
With a heavy infestation of root rot probably start out with about 5ml of bleach per gallon of water. You can even go as high as 10ml.
If you can totally seal off the root zone from all light the bleach should do a pretty decent job of keeping the root rot under control.
At this point, as others have suggested, if it's really bad, you might want to consider starting over, but it can be saved if you start right now with all the steps I mentioned above. As I said, starting out with clean RO water first and foremost will help eliminate a LOT of problems.
If you go the bleach route, make sure to change your reservoir water out regularly, this will help accelerate recovery. Bleach evaporates from water over time. I've had severe cases of root rot (much worse than you have there, I'm sure) that I managed to clear up in a week or two. Just change your res. water roughly every 3 or 4 days. This will obviously use up more of your fertilizers having to change the res. water so frequently, but you'll just have to weigh that against whether you want to save the plants or just start over. All up to you.
Also, if you can, after (or during) you empty your reservoir to change the water, it will help tremendously to open up those buckets and, with your hands and fingers, gently rub the roots to try to get as much slime off of them as possible. Maybe use a sprayer or something to try to "pressure wash" the slimy crap off the roots. This will make a big difference, as well. Get the whole system as clean as possible. Scrub any crap off the sides of your res, clean out your hoses and buckets, etc.
It's not an easy fight, but I find in a lot of hydro systems it's a lot easier to just run a sterile system.
Hydroguard has a shelf life and I've found, usually, when I buy it, it's already expired, unless you buy it from a store that gets fresh stock on a regular basis. But, I've had absolutely horrible experience using
Hydroguard. It's a waste of money in my opinion.
Once you have your root rot totally cleaned up (or if starting over) you generally want to use about 3ml of bleach per gallon in your res. and you can add an additional 3ml per gallon once or twice a week for preventative measures.
I would say, if you can, try to see if any light is getting in at the root zone at all. Maybe you could empty out the buckets and put your phone inside recording a video, then seal it all up. Open it back up, grab the phone, and observe the video and see if you can see any light coming in. Get resourceful and try to figure it out.
Another tip is to make sure your res. water temperature isn't getting too warm or too cold. Generally you want to keep it between 65 and 75 degrees, certainly no more than 80 and no less than 60. Higher res. temps are a good breeding ground of root rot, as well.
There are water coolers available or hydroponics if you search around on Amazon or your local grow store might carry them, but they can be pricey, but also worth it if you have no other options.
I custom fabricated my own water cooling system. I used an old radiator I had (make sure it doesn't leak obviously and clean it out as best you can if it's used). I keep the radiator outside of my grow room with a small fan on it. It generally keeps my water around 68 degrees, but that all depends on the environment it's in, of course. This obviously isn't the best method, but if you're on a budget and you can pull it off, it does work.
One other tip is to make sure your res. is well aerated. Another tip if you're using an air pump is to move the air pump outside of your grow room (or tent or whatever you're growing in) and run the air lines into your reservoir that way. Or, keep the entire reservoir outside of the grow room,/tent/whatever, this may solve a lot of issues all together.
Sorry if this jumbled or hard to understand, I'm half awake at the moment so if you have any questions or need further explanation just hit me up and I'll be glad to elaborate and help as much as possible.
Let me know what ya want to do!
Good luck to you!
Glad those days are behind us!
