DWC root issues (help would be appreciated)

Hi,

/// skip this section if you just want to know my current problem ///

My plants are around 7–8 weeks old, and I am fairly new to DWC. I did a lot of research, and I was reading through a lot of papers about pythium in hydroponics and the actions to prevent it. I know that there is a chemical and an organic way for DWC. I have tried the sterile way with sodium hypochlorite, but I was not very successful. A little story about what happened since I started. I planted the seeds (automatics) in rock wool and the first week I had normal growth. I planted them too early into the system which they did not because they probably had no oxygen because it was too wet for them, even tho I left a gap between the bottom of the pot, but my pump makes a lot of tiny droplets, and it soaked the rock wool constantly. Here I almost saw no growth for the next 2–3 weeks which is obviously not very good with automatics, but I want to learn on this run, so I decided not to start over and dump them. I fix the issue by buying a smaller pump and increased the water to net pot distance. Then there were like 2 weeks when I could see huge growth (still running sterile) but they were still fairly small. I change my reservoir weekly and had to give around 1-2 ppm of sodium hypochlorite every 3 days. I also think they did not like chlorine that much or were very sensitive to it. Anyway, the reservoir temps were always around 68-74, which seems was enough to create root rot. I also witness some white mold on my air stones. I cleaned everything, sprayed everything with a 15 ppm chlorine solution and let it sit for some minutes. I boiled the air stones and got the system back running, but it just stalled the root rot. It is to mention that the root rot was only minor, but I wanted to take actions before it was too late. Since I only want to buy a chiller as a last resort (price and energy reasons and also the danger of water leakage) I will no longer try to keep the reservoir sterile since it is almost impossible to prevent growth of harmful bacteria when the water temps are not in the right place. Also, there seems to be still the chance of root rot at lower temps, which some papers indicate.

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I brewed some Heisenberg tea with TNC MycorrPlus, TNC Tricorrp5, TNC Bactorrs13, Plagron Mega Worm and some unsulfured molasses. I put two air stones with a 3.1 watt pump into the bucket, mixed everything through and let it sit at room temp for 24 hours. I used about 3 liters and used the amounts Heisenberg suggested (but with slightly different ingredients but almost the same). I also switched from GHE TriPart to Canna Aqua Series with Cannazyme (everything at the same time since it was one order). I switched to Canna since I wanted to try their nutrient line and my GHE was almost empty.

To my system:

• 3 x automatics (barnes farm wedding cake)
• 80 liter reservoir (~20 gallons)
• 300 watts but dimmed at 40% right now (around 35-40 DLI)
• first GHE TriPart then Canna Aqua Flores+Vega and Cannazyme (which is redundant with bacteria because they should produce it on their own but I still wanted to use some)
• air circulation should be sufficiant.
• air pump is 28 liters per minute which is about 7 gallons per minute (is higher than the recommended 1:4 ratio)
• about 2 inch gap to the net pot
• PH: 5.7-6.4 (I let it drift in this range)
• EC: 1.2 or 600 ppm.
• water has a start EC of 0.2 and is pretty good water

After my treatment with 3 liters of Heisenberg tea, one day later the plants look like this below. There might be some new growth, but I am wondering if they should look like this after the tea. The solution was quite dark and sure, with microbes everything will be a little gunky, I am still worried since the plants are already in flowering. I also will soon add a biofilter to the system. Could you give me some tips for my next grow? Could you tell me if I am on the right path or if I fucked up too much? I swear I did so much research and I think I understand the concept, I still lack of practical experience with hydroponics. Although, I have done several grows in soil. I would appreciate any help a lot! Thanks for reading through. If I missed any information that might be important, I am glad to provide it.

Anyone knows

Sad roots. I would go sterile since you don't run a chiller. I run 1-3ppm residual chlorine in hydro. It's gonna take a while for the roots to clear out. Organics and hydro doesn't mix well. Hydro is meant to be sterile since the nutrients is in readily available form. Our job is to keep the root zone healthy and clean for optimal nutrient uptake.

I use regular unscented bleach (sodium hypochlorite) at 5% strength. 3ppm is recommended in DWC. Run the diluted nutrient solution with 3ppm residual chlorine through the net pots a couple of times a day to make sure you cover all of the pythium growth. Here's the dilution calculator:
Chlorine dilution calculator

This is a nice picture of your roots! I did not manage to run sterile successful. They improved quite a lot since my post, tho. I will keep trying with beenies for now since it should work better if I cannot maintain proper water temperatures, right?

are your roots slimy at all?

No, they still have major brown spots but I am seeing a lot of new root growth. Also I am not certain the brown spots are even root rot or just the healthy bacteria. I also have added a biofilter to give them a place to live despite the root zone. Also, there is a biofilm everywhere but I think this comes from the good aerobic bacteria. The reservoir is super gunky but I guess thats what it is alowed to be when running with beenies.

I will post some pictures of the root zone in the next 24 hours.

As promised. I think there is still some root rot left but even tho, it is not spreading anymore, and maybe it's only dead cells. The bacteria and fungi seems to be doing a good job at fighting it and competing for nutrients. As long as the plants do not seem disturbed, I think I can pull this through. I am really impressed because 70% of the growth happened in the last two weeks. The plants really did not like the sterile way. Maybe it was of the sodium hypochlorite instead of calcium hypochlorite (never tried H2O2) but the roots were really stunted in their growth. Since I switched to beneficial bacteria, I see massive root growth and overall plant health improvement (I use an adapted recipe, but I follow the Heisenberg tea brewing method. If you want to know exactly what I use, just ask). I did add some new tea today but this time only the continuous dosage (1 cup / 10 gallons). Currently, I am just doing top-ups because there is no reason to fully drain the reservoir when there is so much life going on, but I think I will switch every two weeks to keep bacteria diversity high. I also added an airlifter for test purposes besides my bio filter, which works great.

Canna Aqua Series
PH: 6.3 | EC: 1.5 | Water temp. 23 °C
Smell: from fishy (two days after first treatment and they did look healthy) to earthy/mossy

i had good luck running bacteria(just southern ag) and running sterile. it's weird how some people have trouble with one or the other. but as long as you find something that works for you, good job.

rkymtnman said:

i had good luck running bacteria(just southern ag) and running sterile. it's weird how some people have trouble with one or the other. but as long as you find something that works for you, good job.

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I think running sterile is fine but there are several variables to consider like water source, general hygenic of the room, different strains, strength and concentration of the oxidation substance, water and room temps, light leakage and so on.

For sure there are also several variables with beenies to consider but overall giving up control seems a good trade off to me when it is not possible to keep the reservoir sterile. Also the symbiotic relationship between plants, bacteria and fungi has only been studied intensivly the last decade. There are several papers about the release of certain hormons and antibiotics against pathogens from plant friendly bacteria and fungi but there are still mechanisms that are not understood. It just feels a little bit like magic when adding powderd microlife, multiply it with a tea and let it do its thing.

Yea I mean maybe I will still manage to screw it up when summer hits real bad since I don't have a chiller but fingers crossed that won't happen.

I have never tried mixing bennies myself , but running orca at double strength works well form me in a non chilled system.

i good thing to do also is inoculate your pots weekly to keep the bacteria in your pot above the waterline.

For a week my DWC water temps were between 75 and 85. No root rot, I think Southern AG might be doing its job cause I anticipated the water to go nasty in those temps.