How do I clean an RDWC system & roots?

I’m not only new to growing cannabis, but also new to hydroponics as well. I’m about a month into veg and noticed the roots are starting to look a bit discolored. I’m ready to do a nutrient change and thought it would be a good opportunity to clean the system. I saw a YouTube video of someone doing this with H2O2, and I’ve also heard of including H2O2 in your nutrient solution to keep things clean. I’ve been using Hydroguard along with my GH nutes. My water temps are high (70-72°F) and I’m trying to keep them lower using frozen water bottles. Thanks for any and all advice!

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If you are using organic nutes…like worm casting related stuff, it will stain the roots medium brown. I prefer bright white root systems.
Good luck

Roots will turn dark if your having root issue such as root rot or because chemicals staining them.
Not sure of your type of system, if you want to alleviate the possibility of root rot, I would highly suggest getting a chiller. Some get by without one and others can not. I have one and have never had any root issues, (yet).

When changing your water out, you can run some hydrogen peroxide mixed in with your water to help clean the roots if you have root rot. But do not run the peroxide while you have nutes in there. If the plants don’t show sign of issues then it’s probably just stained.

This will help the community know how to help better if you care to answer these questions.

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COPY/PASTE the below list into your forum post.

Answer these simple questions the best you can.
If you do not know, or do not use something; Just say so; Or post
NA (non applicable)

What strain, Seed bank, or bag seed
Age of plant
Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF
Vessels: Pots, Grow beds, Buckets, fabric pots
PH and TDSof Water, Solution, runoff (if Applicable)
PPM/TDS or EC of nutrient solution if applicable
method used to measure PH and TDS
Indoor or Outdoor if indoor, size of grow space
Light system LED, MH/HPS/CMH/Fluorescents, or other
Actual wattage draw of lights
Current Light Schedule
Temps; Day, Night
Humidity; Day, Night
Ventilation system; Yes, No, Size
AC, Humidifier, De-humidifier,
Co2; Yes, No
If growing Hydro some additional questions:
DWC? RDWC? Autopots? Ebb and Flow? Other?
Distance of liquid below net pot (DWC)
Temperature of reservoir
TDS of nutrient solution

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Good luck! :v::+1:t2::sunglasses:
P.S. We like pictures!! (Natural light)… :wink:


When i do res cleaning and changes i always do a whole bottle. Of 3% peroxide in a 5 gallon bucket of water. While i clean the bucket and whatever i set the root ball in the hw02 mix. Every 10 mins or so i pull out plant rinse off roots with shower head not super hard but a brisk spray so it knocks off any loose buildup. Wotks hreat roots come out nice. Just make sure to thoroughly rinse the roots super well before adding back to nute water cuz peroxide will kill anything good the plant needs. Hydro guard is a must for hydro styles. Works well and saves some headaches. Do u add hydro guard after u ph the nuyes right??? Hydro guard will up the ppms of the water and u dont want that in the final ppm reading always add hydro guard after all nutes and u r phd to ur 5.8 setting

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What size bottle of H2O2 do you mix into the 5 gallons of water? Thanks!!

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@Myfriendis410 @peachfuzz how much peroxide do you mix per gal clean roots?

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3/4 cup of 3% for 3 gallons and mabe a cup and a half for 5 gallons … :+1::wink:


And I usually do 1 cup in 5 gallons


@Myfriendis410 @peachfuzz thank y’all for that! :+1:t2::v::sunglasses:

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This is great information !!

Though I have never used this method I am curious with what solution I can run through my system after grow is complete. Something I can refill system and run a few days or so to clean the lines before I drain and wipe down system.
Any ideas ?

I have always updated and made system larger so far between grows so lines were replaced. Now system is at max size for grow area.

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After I harvest I pour a whole bottle (32oz) of peroxide in the system (22 gal) and let her run. My lines are 1 1/2” so I’m able to take them outside along with the buckets and run the water hose with a wide sprayer through them.
Cleans them out nicely. And then just scrub down my totes real good.
I’m gonna be changing to 3/4” pvc after this grow, so I may have to come up with something else to clean them with.
Hope this helps or answers your question.

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To be clear, after harvesting you add the bottle of peroxide to your existing nutrient solution and let it run, then rinse it all out, correct? Also, I’m assuming your H2O2 is the 3% variety, right? Thanks!!


Dump solution, rinse, run strong peroxide solution and allow to dry. Peroxide dissipates with no residue.


@spyonyou @Myfriendis410

Thanks so much for the explanation, I will for sure do this.
It’s probably 50 gals or so in system. Might need 2 bottles.


You’re more than welcome. For what it’s worth, I meant to say I am changing out my 3/4” garden hose for pvc. I’ll keep the 1 1/2” pvc input. 3/4” output. :+1:t2::v::sunglasses:

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