How do I identify and prevent Root Rot?

Smokin Moose

Fallen Cannabis Warrior & Ex Moderator
Introduction - Background - Id & Damage - Management Strategies - Emergency Treatment - Prevention - Environmental Control - Additives

Introduction
"Root rot" is a common waterborne disease that can seriously affect indoor and outdoor crops year round. "Pythium" is a generic term for several different root rot and stem rot fungus species (including Pythium, Verticillium, and Phytophthora, and Fusarium). Root rot is also known as "damping-off" in seeds, seedlings and clones.

Pythium can rapidly infect crops in vegetative and flowering stages. Damage includes strain infection, reduced yields, and crop failure. Pythium is particularly damaging in high-density dwc / hydroponic / aeroponic systems, as these recirculating systems provide ideal conditions for rapid growth and spread of pythium spores. One infected plant can quickly spread rot to all plants if the system has an interconected irrigation system.

This FAQ focuses on indoor prevention and treatment options.

Background
Pythium typically thrives in oxygen-poor (anaerobic), warm (75-85 F), and poorly circulated nutrient solutions. Heavy clay soils with poor drainage are high-risk soil planting sites.

Sources of infection:
# Unsterilized tools and equipment
# Unfiltered water
# Dead roots from previous crops
# Infected plant material (i.e. clones taken from infected moms)

Dissolved oxygen, temperature and pythium
The amount of dissolved oxygen (DO) in a nutrient solution depends on the water temperature. Cold water can 'hold' more dissolved oxygen. A fully aerated solution at 20C/68 F is 9 - 10ppm; at 30C/86F it's 7ppm.

Root oxygen requirement doubles for each 10C rise in root system temperature (max 30C/86F). The dilemma for the grower is that with a 10C rise in temperature, root system oxygen requirements will double, while the oxygen carrying capacity of the solution will drop by over 25%!

The nutrient DO is unable to supply the root's oxygen demands, leading to prolonged oxygen starvation. Oxygen starvation will result in slow growth, mineral deficiencies, root die-back and reduced yields. Oxygen starvation will stress the plant, leading to an eventual attack by opportunistic pathogens, such as ever-present pythium.

Identification, Symptoms and Damage:
Symptoms:
Initial:
# Yellowed, droopy and wilting leaves (possibly exhibiting mineral deficiencies). Leaf curl over - ram's horns' - roots are unable to uptake nutrients at that strength because they are infected.
# pH becomes more acidic (pH should rise slowly in a healthy system)
# 'Burnt' root tips (browning tips may also be a result of light exposure, or over fertilization)
# Reduced water consumption and rising nutrient strength
# Brown colored roots. (Note: GH "Micro" will stain roots brown as well; stain darkens @ ppm's. Healthy root should be white or slightly tan)

Advanced:
# Brown and slimy roots with a slight to strong rotting odor. Plant may appear healthy.
# Reddish and swollen root collar, becoming blackened over time. Eventually the plant will fall over as all connecting tissue will have been 'eaten away'.

Note: Root damage is permanent; new root hairs can form, but damaged roots will not regenerate. Lightly infected roots may turn white again if treated promptly.

Dead roots serve as energy sources for pythium; snip off dead roots and remove flating root piece by changing the tank frequently.

Physical test of advanced root rot:
"Brown tissue on the outer portion of the root easily pulls off, leaving a thin strand of hair-like vascular tissue exposed."

Management Strategies
Keeping the crop healthy, vigorous and stress-free is the best "cure" against pythium. Pythium is almost impossible to 100% eradicate from an infected system; this involves starting completely over (with new mothers, containers, equipment, etc). An infected crop can be nursed along, and subsequent crops can still yield, provided the grower takes care to minimize the growth and spread of pythium in the system.

Starting with a pythium-free system is the best strategy:

Startup with a new crop:
-disinfect the system. Manual scrubbing and bleach might be necessary.
-add tap water
-disinfect the water with strong h2o2. It takes 100ppm to kill pythium outright, however this can also kill small plants. Wait 24 hours for h2o2 to dissipate to a safe level - do not add tap water to system! Add only h2o2-treated water.
-add nutrients and beneficial enzymes. The aerobic-loving enzymes will colonize the sterilized medium and system, hopefully displacing any anaerobic bacteria.

Soil tips:
Improved soil is the first step to keeping root rot out of your garden. Adding amendments to improve drainage and aeration will decrease the chances of root rot. Use only sterilized soil/soilless mixes or heat-treated soil before use.
Removing the diseased plants and several inches of affected soil will slow or stop the spread of pythium. Avoid over watering, as saturated soil promotes anaerobic conditions. Remove and destroy roots and surrounding soil near infected plants. Use sterilized soil for transplants. Provide good drainage and avoid overcrowding plants.

Preventive gardening:
# Monitor plants and roots frequently. Inspect roots for browning. Stressed plants are attacked first, so it is important to inspect crop and remove unhealthy plants.
# Maximize aeration. Use venturis, powerheads, bubble walls/ air curtains, air stones, and daily h2o2 usage to increase dissolved oxygen. Allow nutrients to fall back into the reservoir to create 'waterfall aeration'.
# Use only healthy clones taken from healthy moms (pythium is systemic and diseased moms will pass on root rot!)
# Keep ph stable, between 5.5 and 6.0
# Keep air moving, circulate nutrients continuously
# Keep reservoir / root zone temps low: 62-65F.(Note: submerged pumps will increase water temperature)
# Maintain a clean system. Change tank weekly to reduce spore loads. Add only h2o2-sterilized water
# Use tank additives

Other tips:
# Isolate plants. Keep water culture plants isolated in their own containers if possible.
# "Run-to-waste" systems: nutrients are not re-circulated = reduced spore loads
# Use separate reservoirs/pumps to isolate systems.
# Sterilize equipment shared (ie. pH meters) between tanks
# Make sure cloning mediums (especially rockwool) do not remain saturated for too long. Drain fully after watering.

Special tips for bubblers:
(highgrade) "Have an empty, sterile bucket to place the bubbling bucket into when changing nutes. The extra bucket method allows me to run a gallon of water through the pot and flush the grorocs and root mass of any salt build up. Wash the bucket prior to refilling with solution."

(Baudelaire) "... maintain a humid air gap extending from the root crown down at least 4 inches. This provides the space for aerial roots to form, and keeps water away from the root collar, where root rot typically takes hold."

Emergency Treatment: top

1. Hydrogen Peroxide root dunk
-Remove each plant from system, snip off potions of the roots system badly diseased.
-Dip/swish each plant and container into a strong H2O2 solution, until diseased roots have been removed. Repeat as required. The H2O2 should burn off the pythium-infected outer root layers.

2. Sterilize equipment
All equipment should be disinfected (including hoses and pots, etc) with bleach solution or 10% h2o2 solution before plants are reintroduced into the system. Rinse well.

3. Add root rot medication.
Add anti-pythium additives, Vitamin B1, and fresh nutrients to a sterilized reservoir at a lower strength, at cooler temps. Reduce light levels. After a week or so, after new roots appear, add some root boost additives.

Environmental control: top

# Maximize reservoir circulation, aeration and cooling
# Reverse Osmosis (RO) to remove pathogens from source water
# UV sterilizers. UV kills pathogens as nutrients are passed through unit
# Ozone. Maintain a 300-400mV level
# Blow cool air through the root zone
# Minimize light leaks and cover reservoir (but don't seal) to limit algae growth. Algae will grow, reproduce and die, adding organic material for pythium to feed on. Algae and other slimes may coat the roots, stressing plants even further.

*Take care using UV and Ozone, as nutrients can precipitate out of solution. Iron is especially susceptible.

Chemical/Biological additives: top

Note: H2o2 may kill enzymes used in some biological additives. Additives should be considered preventive only; not all additives may be effective.

Beneficial bacteria colonize the root system, out-reproducing root disease organisms. Some additives may "feed" on decayed roots. Additives may be added during every tank change, except for H2o2 and Ridomil.
-H2O2 (See H2O2 FAQ) -Ridomil (1 app, systemic, toxic, 5 drops/gal).
-FloraShield (by GH) -Bio Bugs
Guardian angel (2.5-5 ml/gal) Bio Bran (rambridge.com, 11 enzymes)
Root Shield (americanagritech.com) Sm-90 (citrus extracts @ 2.5 ml/gal)
Hydro Shield (grotek.net) Pro-Silica (silicon, basic, up to 5 ml/gal)
Microkill (kills mold/fungus/mildew/algae) Pro-TeKt (silicon)
Canna-zyme (Canna, canna.com, 15 different enzymes) Power Active
ATAZYM (Atami) BN-ZYM (bio nova)
Zyme (Green Planet, 6-8ml/gal)
Others: Ascend/Fongarid/Consan 20)/Fosetyl-A1 (sold as Aliette)

For seeds, seedlings and clones:
# Use 1 drop bleach/gal when sprouting seeds using towel method
# No-damp (spray cloning domes at 5-10ml/L)
# Cloning gel/powder with a fungicide

Experimental
# UV Sterilizers. UV can kill waterborne organisms, with a slow exposure to UV light. Research suggests iron can precipitate out of solution. Pythium already attached to surfaces in the rootzone will not flow through the sterilizer and not be killed. Aquarium stores sell them.

# Continuous drip H2o2. According to Maximum Yield, 100ppm is required to kill pythium in solution. This level also adversely affects small plants. Of course, organics and beneficial bacteria in additives will also be destroyed.

H2o2 should be added to a seperate volume of water and allowed to sit for 20 minutes before adding to the reservoir. The majority of the O2 will be chemically released by the H2o2 by that point. (In high enough concentration, h2o2 will burn off the epeidermis of the roots, exposing it to attack by pathogens and damging fine root hairs).

# Slow sand filtration. According to interet literature, SSF can remove up to 99.7% of all bacteria. Aquarium stores sell sand filters.

# Dissolved Oxygen machines. Artifically injecting water with oxygen may inhibit or kill pytium and other anerobic organisms.
 
I f-ed up & now i have root rot with my out side plants. what do i now to save them now? i have lost 2 plants & now one more is gowing. I have dug out dirt around the botten of the plant to get air down at the roots. & i got roots exceluraror so what else can i do? to save the rest of my plant's??
 
Canna makes a really good solution for root rot. It's called Cannazyme, and what it does is strengthen the roots, prevent root rot and also eats your dead roots so it doesn't feed root rot. It goes for about 10 dollars for a small bottle (8 oz i think). Haven't really tried it (my temps are about 72 or so so my water isnt warm enough for it) but i heard its really good. its made by Canna so that already says something.
 
"1. Hydrogen Peroxide root dunk
-Remove each plant from system, snip off potions of the roots system badly diseased.
-Dip/swish each plant and container into a strong H2O2 solution, until diseased roots have been removed. Repeat as required. The H2O2 should burn off the pythium-infected outer root layers."

Anyone know what this mix is on this (peroxide to water)?
 
To prevent Root Rot, adding product's like Thrive Alive B-1, See Weed, Super thrive will help protect your plant's from root rot and will help cure root problems.
 
It seems like I've been fighting root rot since growing tomatoes and peppers as a kid.

Over-mulching can get you if you're growing in an area that's hot but with a good amount of rain. Mulch keeps the soil cool in the day and the water in. The down side is at night a heavy layer of mulch keeps the ground temps up in the sweet spot for root rot and air circulation at the base of the plant down.

If you get root rot in a spot one year,just move on the next.

Prep your soil to encourage drainage it can be simple. In the clay soils I dealt with,a little gravel and sand can do wonders. If the gravel is limestone it can be a bonus in mild neutralization of acid soils.

If you're lucky enough to live in a state that allows outdoor med grows,you can get into, say,a pepper,clover,weed rotation. Pepper roots loosen hard/dense soils,clover adds nutrients and you know what the weed is for. Peppers in '10,a clover crop for the winter,and weed in '11.

Don't use vermiculite/perlite if you're doing outdoor guerrilla grows. That stuff gets spilled getting carried in,gets on the soles of your shoes,etc. It stands out like a sore thumb on the ground in the woods,leaving a lil' Hansel and Gretel trail directly to your weed patch.
 
i got root root and lost my outsie crop to fungus and pythium due to excess rain. i use pirranha tarantula on every plant for preventive maintenance. havent had a problem since.:peace:
 
I've tried Pirana, Turantula, Great White, Roots Excelerator, SM-90, Hygrozyme, H2O2, B-1, Superthrive, Physan 20, Algaefix, cut off light to res, etc... YOU FREAKING NAME IT, AND NONE OF IT WORKS!!! I've been doing this for more than 10 years now and have never had this problem! What gives

PS - Talked to a plant lab and PYTHIUM/ROOT ROT IS NOT SYSTEMIC!

Going back to the only thing that is reliable and has ALWAYS worked, DIRT!

Anyone got any more ideas that don't work? lmao

Can you feel my frustration? lmao

Please help!
 
sorry man if none of that worked.
i do feel your frustration.
i would flip out and start over. call it a loss.
thats just me though.
i lost my crop too 3 5' plants. i was so bullshit.
and there was nothing i could do. i used everything too.
i think once you got it it never goes away.
:peacetwo:
 
:morenutes:
I feel everyones pain here on root rot. I run DWC Bubbler Tub. I tried everything to get rid(Bleach, Hydrogen Peroxide 3%, H2O2, SM-90, ect) it would die back but never completely go away, I was ready to pull it to start over & finally found it took a couple of things to get it completely handled. #1. Must use RO water if you have rot(recommend it even if you don't) #2. you can H2O2 root dunk all you want, still comes back #3. Do not listen to the local hydro shop they don't know in most cases #4. watch those res temps(never over 75 degree F if can help it) #5. put the most amount of air stones in the res water that is reasonable (my 10 Gal res of which I keep 6 gal H2O have 3 large Air Stones ea). My local Hydro shops in my area (3 in all) all said H2O2 dunks, 5ml/gal in res & use Hygrozyme; things went from bad to worse because it turned into the worst thing I ever seen, I got water mold (snottiest looking shit I every did see). Finally the thing that turned it all around was Dutch Master Gold Range Zone, and it was like night & day. 1 day things had improved greatly, 1 week had snow white explosion of root in res, 2 weeks no signs of anything but what I wanted in there! The proof is documented in my current grow journal! I was hoping just to limp through to the next time, & just chock it up to OJT but now have very high expectation on the finish weight of the grow! :goodluck::slide::thumb:
 
I liked your message about getting rid of root rot. I have also encountered this problem in my hydro system. Since you spoke so highly of the gold zone I purchased some myself. I was using hygrozyme and aquashield but still no real success to talk about. Hygrozyme is so expensive too! I am on my 2nd grow in a BCNL bloombox. Do you mind sharing how you grow with a newb?
 
Using dutch master gold zone with advanced root rot, do I still need to add the h2o2 every other day?

My girl went from full flower (3 weeks until harvest) to mostly dried up. I took aggressive actions, but the buds seem to have died. If the plant revives, should I cut off the dried buds and just let it start flowering all over again?
 
My biggest girl has a bad smell, and the baby clones don't look happy. I am heading out to get some super thrive at the hardware store, and putting Dutchmaster Gold Zone on my Christmas list.
 
ugh I had to worst smell on my big girl this morn...

The clones near by are not doing well, however I checked one empty container
(waiting for a new clone) and there was no smell- so I am hoping to nip this on the bud... no pun intended.***
I'm on day 35 of flowering - things seem to have slowed down. I'll go get some super thrive to start TODAY.
Dutchmaster Gold Zone is on my Christmas list... I have to teach all this to my mother who will be attending to my plants during surgery in a couple weeks. :love: Isn't that a hoot!

***...although I just had to nip a bud or two for the holiday. I had couch lock and the pistils are still white!
 
Greetings all. I am currently fighting the most tenacious strain of what I just found out was "Pythium" This stuff can actually withstand and flourish is a solution of 1/2 cup of bleach followed by 60 Ml of zone in a cloner that holds about 8 gallons of solution.

I am running a NFT System and this stuff is laughing at dutchmasters zone. Its laughing at everything I throw at it. Hygrozyme, Gro-Tek silica, Companion, SuperThrive and 40Ml of bleach per gallon of water. I have tried combinations of all kinds and this stuff just laughs like the possessed child in the movie ...the Exorcist.

My next attack is going to be as follows....Remove plants..then bleach everything ( 2 cups bleach to 5 gallons of hot water ) Ie...res, pumps, lines, nft troughs. Then Im going to fill the res with water and add 60 Ml of bleach to 10 gal's. Next...each plant will be soaked in hydrogen peroxide for 1/2 hour each and then be added back into the nft system. Im running three plants per 10 gallon res and to that I am going to add 60 Ml zone folloewd by 60 Ml of gro-tek silica solution, 10 drops of SuperThrive and my nute's. Im going to run that for 48 hours and then add hygrozyme and run that 24 hours and then follow that up with companion to eat all the dead stuff.

I know that its going to laugh in my face again but Im studying the behavior of this Satanic Demon and here's what I have found out so far

This strain of Pythium seems to flourish when the plants are under the light light cycle. I have removed plants that started suffering collapse and they seem to sort of come back when taken out of the res and placed in a place with very little light ( garbage can in the corner of the room) The stuff can flourish in a cloner solution with 1/2 cup of bleach and 180 Ml of Dutchmaster Zone.

This is Insane and any help from the group would be most appreciated however please dont speculate. I need people who know, not people who Think they know.

Thanks
Dr Gonzo
 
I would not use the bleach, it will harm your plants even worse.

I've just finished batteling this myself, although I grow in soil and not hydrponically. I used hydrogen peroxide as a flush on my plants, followed by a higher nitrogen feed.

Identification: Starts in lower fan leaves dieing, and progressively works its way up the plant until it starts killing the colas.The plants can not gain their needed nutrition via the roots, due to the fungas blocking the root uptake, so the plants try to stay alive by robbing the leaves of what they need to stay alive. The roots turn a tan or brownish color, and will die as well. It can be a little difficult in the early stages, to identify this just by looking at the leaves, as it looks a lot like nutriant def ( which it is ). Many people try to treat it by feeding more, or less if they think it is lockout. This does nothing, as the roots cant absorb what they need. The dead sure way to identify this is by root color. The roots should be a nice white color in a healthy plant, and off-color in an infected plant.

Treatment: I have seen several concoctions in the hydro stores that claim to treat this, and well they might. But I havent used them. Instead what I did was to purchase 28% hydrogen peroxide at my hydro store and mixed it at the rate of 5 ml. per gal of water and I used this to flush my plants. Following the flush I fed with a grow nutriant solution, because they are starving for nitrogen ( and everything else). Within a day I saw results. New growth starting, plant perking up and adding needed moisture to the dieing areas. In a couple of days I saw lots of new growth. I repeated this about a week later, and again when it looked like they needed it. Even though I did the initial flush over a month ago, I still see a need to repeat once in a while. I think ( not real sure about this) that even though the h2o2 kills the fungas in the root zone, that some still lives within the plant, causing re-infection, neccesitating the repeat flush. I feel that I will need to continue treating the infected plants until harvest.

Bleach KILLS plants. Use it to clean your resavores, tools and equiptment, but don't let it touch your plants or roots!!!

hope this helps
 
I would not use the bleach, it will harm your plants even worse.

I've just finished batteling this myself, although I grow in soil and not hydrponically. I used hydrogen peroxide as a flush on my plants, followed by a higher nitrogen feed.

Identification: Starts in lower fan leaves dieing, and progressively works its way up the plant until it starts killing the colas.The plants can not gain their needed nutrition via the roots, due to the fungas blocking the root uptake, so the plants try to stay alive by robbing the leaves of what they need to stay alive. The roots turn a tan or brownish color, and will die as well. It can be a little difficult in the early stages, to identify this just by looking at the leaves, as it looks a lot like nutriant def ( which it is ). Many people try to treat it by feeding more, or less if they think it is lockout. This does nothing, as the roots cant absorb what they need. The dead sure way to identify this is by root color. The roots should be a nice white color in a healthy plant, and off-color in an infected plant.

Treatment: I have seen several concoctions in the hydro stores that claim to treat this, and well they might. But I havent used them. Instead what I did was to purchase 28% hydrogen peroxide at my hydro store and mixed it at the rate of 5 ml. per gal of water and I used this to flush my plants. Following the flush I fed with a grow nutriant solution, because they are starving for nitrogen ( and everything else). Within a day I saw results. New growth starting, plant perking up and adding needed moisture to the dieing areas. In a couple of days I saw lots of new growth. I repeated this about a week later, and again when it looked like they needed it. Even though I did the initial flush over a month ago, I still see a need to repeat once in a while. I think ( not real sure about this) that even though the h2o2 kills the fungas in the root zone, that some still lives within the plant, causing re-infection, neccesitating the repeat flush. I feel that I will need to continue treating the infected plants until harvest.

Bleach KILLS plants. Use it to clean your resavores, tools and equiptment, but don't let it touch your plants or roots!!!

hope this helps

Thanks Randm. I haven't been able to keep starts living past 3 week before total collapse. Always the same thing and this stuff has a grip on my mothers. I'm going to try and take some fresh clones from parts of the existing mothers that don't show any signs of red colored veining. My plan of attack is to take a cutting and place in h202 for a few minutes and then move the cutting to my clonex cloning gel. After Dipping in the cloning gel I will then place them in a fully sterilized (with Super Strong Bleach Solution) Cloner. This will include the rubber disks. The solution to be placed in the cloner will be as follows. Water mixed with H202 and 60 Ml of dutchmaster Zone pluse 60 Ml of Gro-Tek silica solution and 200 Ml of Clonex Nute's and Ph ed to 5.2. I will then wait 2 days and add Hygrozyme and wait another 2 days and just watch and see what happens. I may then elect to add the recommended amount of Companion to eat any dead stuff.

When I soak my rock-wool blocks I will sterilize with a h2o2 / dutch master Zone solution and let sit for 12 hours and then Ph to 5.5 for another 12 hours before blocking up the clones from the cloner. The blocks will be kept on the dry side and dipped in an h2o2 / food solution every 2 days until ready to be placed in a fully sterilized NFT trough loaded with a h2o2 sterilized dutch master Zone Soultion using house and garden Nute's and Gro-tek silica for a total Ec of 1.1 and ph'ed after 24 hours to 5.2.

This is the tentative plan but as always I welcome anyone with first hand knowledge to pick my plan apart for flaws. Side note: all steps and measurements will include dipping all tools and meter probes in 99 % alcohol to prevent any cross contamination. Im also looking into inline UV-C water units to be placed inline between my feed pumps and my feed emitters.

thanks
Dr Gonzo
 
sounds like a plan. When I first got the 'borg', as I said, I had no idea what was going on. I cleaned the crap out of everything with bleach, sulfer bombed the rooms ( grow and flower) strerilized my cutting and other implements. washed the walls, floor, ceiling , light fixtures and everything with bleach water.

AND IT STILL CAME BACK!

i WAS THIS CLOSE TO CALLING IT QUITS! *-*

When I finally got a hook on what was causing it, and started using the h2o2 flush, I was amazed at how easily and completely they came back from the dead. I still give an occasional h2o2 flush on any plant that starts to look like that and I'm back on track to a good harvest. ( knock on wood)

I like the uv-c idea, if you can afford it go for it.
 
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