RDWC, DWC sterile research - my findings, some Q/A

SOLVED, SEE:
https://www.icmag.com/ic/showthread.php?t=332696



After 2 years battling root rot, I compiled some knowledge about "sterile" RDWC growing. Please, feel free to correct me.
Please, no "get a chiller, temps are high, more oxygen etc." comments. I have perfected everything, even overkilled ALL technical aspects already.
Using tea for last 4-5 grows and still got problems. And I did my homework about the tea and exhausted all possibilities, even adding it daily at stupid amounts. It did help some, though.

So, here is my "sterile" findings:

-Using Chlorine(bleach) or H2o2 is USELESS without ORP/redox meter AND some sort of automatisation to hold your target levels. ORP levels (in mV) tell you how much of your disinfectant is actually doing the dissinfection.
Example: I have put bleach in my infected system, calculated amount to reach about 2ppm. After 1min there was NO active chlorine in the system. Ended using 50x(yes!) the calculated amount to reach 2ppm!!!! And currently still using 5-10x the amount to correct the levels. Here is the answer, why many people claim, that bleach/h2o2 does not work.

- OPR/Redox potential in mV used for dissinfection is from 420mV-800+mV. Beware, colerration betwen mV and ppm of active chlorine is heavily depended on pH!
700+mV will kill everything, but hopefully not your plants. at least 500+ is reccomended for keeping the res clean.

-In case of using Physan (or hydro-fungicide - I think it is very similar) does not produce any ORP levels. Basically you are adding it blindly. (You shold add it every 3-7 days)

- Using pool shock is I think better, as it is calcium compound vs the normal bleach, which is Natrium based.


SO HERE IS MY PLAN:
- I bought the ORP controller on ebay (careful, some have very limited range of control)
- I plan to run the system with pool shock, stable at around 650mV, which is about 0,5ppm at pH 6.
- occasionaly will shock the system with 1,5ppm active Chlorine (around 800mV)

-Thinking of running my 2nd system with physan, 1ml/10gal every 3-4 days to compare.

Any thoughts, comments, questions?

Thank you!

Sup D350 i am a novice to growing and i would be lying if i said i understand everything in your post. What i do not understand is how and why you have been plagued with this for two years. Obviously you have corrected and over corrected all the basis. And does this happen with any strain? Are you using RO water and if not could it be something overlooked in your water system? Now i am just throwing that out there since everything else has been covered, because there is no reason why this should be happening. Also be careful with that shocking the water technique that sounds scary to me. My novice 2 cents.

I am super excited to follow along and learn from you D350
I quit trying to run Deep Water because of always getting rot and went to RockWool cubes. I've always wanted to get back into it and if nothing else finally get a few successful runs under my belt but really am looking forward to shorter veg room time
Thanks again

https://www.icmag.com/ic/showpost.php?p=6686952&postcount=159
https://www.icmag.com/ic/showpost.php?p=6686959&postcount=160
https://www.icmag.com/ic/showpost.php?p=6700071&postcount=161

mojave green said:

https://www.icmag.com/ic/showpost.php?p=6686952&postcount=159
https://www.icmag.com/ic/showpost.php?p=6686959&postcount=160
https://www.icmag.com/ic/showpost.php?p=6700071&postcount=161

Click to expand...

Thanks for that, seen it before, did not know, someone already posted it here. Tons of useful info.

gardener60 said:

Sup D350 i am a novice to growing and i would be lying if i said i understand everything in your post. What i do not understand is how and why you have been plagued with this for two years. Obviously you have corrected and over corrected all the basis. And does this happen with any strain? Are you using RO water and if not could it be something overlooked in your water system? Now i am just throwing that out there since everything else has been covered, because there is no reason why this should be happening. Also be careful with that shocking the water technique that sounds scary to me. My novice 2 cents.

Click to expand...

Covered all bases: UV-ed RO, tea by RichieRich, tea by microbeman, you should see my collection of air pumps, water pumps, air stones, air lifts, venturi bubblers....
There are anaerobic pockets formed in my root zone (mostly in the hydroton), where the infection starts around week4 of flower.
Some strains are more resistant, some less. AK47 fought a good battle, but lose...
Tried before with sterile and it did not work, I'm very sure it did not work because no ORP meter, just adding some bleach is not enough.

As the shocking goes, instead of running high ORP levels constanly, I plan to rise it for a short time, let's say weekly, just to kill the spores also, not just developed organisms. Plants can take it - although I'll let you know, what will happen in week or so...

Get a bio filter fighting bacteria is just not the easiest way!
Once beneficial bacteria are established they will keep rot away and act as a ph buffer,this has been working for me in rdwc for 10 years.
Peace

ArizonaMeds said:

I am super excited to follow along and learn from you D350
I quit trying to run Deep Water because of always getting rot and went to RockWool cubes. I've always wanted to get back into it and if nothing else finally get a few successful runs under my belt but really am looking forward to shorter veg room time
Thanks again

Click to expand...

I was thinking of quitting DWC also...after crop after crop things got worse...but I'm pretty stubborn and when DWC works it is amazing.
This sterile round will be my last attempt, otherwise I'll join you...

abuldur said:

Get a bio filter fighting bacteria is just not the easiest way!
Once beneficial bacteria are established they will keep rot away and act as a ph buffer,this has been working for me in rdwc for 10 years.
Peace

Click to expand...

been there, done that.
Insane amounts of tea, biofilters, etc...all done. All!!!
It does help somewhat though...

Rot can be caused by many things. Not always bacterial or fungal. You could be fighting the wrong battle.

I changed my net basket size to accommodate a little hydroton under the rockwool cubes. This stopped my issues with rot directly below the net basket. I've seen people's roots turn to mush from the mechanical damage caused by turbulent water.

What are you using as chlorine to disinfect? I use sodium hypochlorite at a calculated 5ppm, I copied this from Wikipedia: "Sodium hypochlorite is practically and chemically distinct from chlorine". I only use it in my aero cloner as there's no temp control. I was informed that hypochlorite isn't very effective against fungal pathogens so I use temperature control primarily... H2O2 shouldn't be used around growing food crops as they store it in the cells. Think of it as a cleaning agent, that's it.

My water comes either from the tap which has high chlorine here or from a store of Ro water that is continually running through a UV filter.

I've had pythium before and used UV to limp the crop to harvest, which causes Fe to drop out of solution so needs to be added back.

You really need to prevent it getting there as much as possible or theres a battle to be had every time.

If you've had it every run for 2 years, with proper temp management, sterile systems and bacterial teas, the problem might just be somewhere else..

Try a different medium like diatomaceous earth instead of hydroton and keep everything the same.

Water culture isn't generally as unforgiving as it seems to be for a lot of hobby cannabis growers.

Peace
BL

Billy Liar said:

Rot can be caused by many things. Not always bacterial or fungal. You could be fighting the wrong battle.

I changed my net basket size to accommodate a little hydroton under the rockwool cubes. This stopped my issues with rot directly below the net basket. I've seen people's roots turn to mush from the mechanical damage caused by turbulent water.


BL

Click to expand...

Thank you for yor answer, valid points.
First, how did you change your net basket? Made them smaller or bigger? I have some smaller net pots ready for my system...

Otherwise, I tried sterile once, but had insufficent knowledge and it all ended badly... With tea I had some good crops, but lately it is getting worse. And it is a real pain in the ass making tea constantly... So, this time I will try with Calcium hypoclorite (pool shock).

Any more advice on net pots?

Everything else I eliminated already...

Thank you

As a aquarist of many large reef aquariums and fresh water aquariums 300+ gallons ill tell u this if u didn't use a UV sterilizer of 50w or more it wont do the job of killing slime or algeas only a certain handful of algea spores and no parasites at all are even effected below 50w The next thing is contact time with UV sterilizer Needs to have a certain contact time to be useful to kill certain algeas and parasites

D350 said:

Thank you for yor answer, valid points.
First, how did you change your net basket? Made them smaller or bigger? I have some smaller net pots ready for my system...

Otherwise, I tried sterile once, but had insufficent knowledge and it all ended badly... With tea I had some good crops, but lately it is getting worse. And it is a real pain in the ass making tea constantly... So, this time I will try with Calcium hypoclorite (pool shock).

Any more advice on net pots?

Everything else I eliminated already...

Thank you

Click to expand...

I made a design error and tried to use the same 50mm/2" net baskets that fitted the aero cloner. In that size basket there's only space for the 1" rockwool cube. I keep water level to the bottom of basket. So I made a new top for my cloner and made the holes bigger in my flower system. Now I root into 1 inch RW cubes then once rooted they now go to a 3 inch basket with a handful of hydroton around and under the RW cube. This has stopped the rotting directly below the baskets. I was chasing nute deficiencies and losing a few plants each run. Now all seems better, no plant loss, better faster root growth and of course that transpires to better vegetative growth.

Hope that helps.

Peace
BL

Billy Liar said:

I made a design error and tried to use the same 50mm/2" net baskets that fitted the aero cloner. In that size basket there's only space for the 1" rockwool cube. I keep water level to the bottom of basket. So I made a new top for my cloner and made the holes bigger in my flower system. Now I root into 1 inch RW cubes then once rooted they now go to........... t transpires to better vegetative growth.

Hope that helps.

Peace
BL

Click to expand...

Thank you for clarifiying. I grow in 8in pots and I think the problems start somwhere in the pot...using 1in rockwool, so not the same thing

I'm sure I've read either dr Lynnette Morgan or someone else saying you can run hypochlorite at 200ppm to treat problems! Don't quote me though, just a brain fart lol..

Peace
BL

Billy Liar said:

I'm sure I've read either dr Lynnette Morgan or someone else saying you can run hypochlorite at 200ppm to treat problems! Don't quote me though, just a brain fart lol..

Peace
BL

Click to expand...

Hehe, I think that was for soil... In hydro 200ppm would kill plants and you haha
As I understand, abive 1ppm will kill most, around 0.5 will maintain it clean. Talking about free chlorine!

Yes 5.5ppm for maintaining a sterile res and I'm still sure there was a 200ppm for treating infection but can't find the source.. never mind, my memory does strange things sometimes hehee..

Peace
BL

I've always using hydroton rocks in the Dwc net pot and tossed a the 1" cloned Rw cube. In the middle so the roots grow into the rocks and into water. Never had an issue though. I'm trying to build a simple 2 Bucket RDWC with a 10 gal Tote As control now. Don't know how it's going to work out or not. But any help is great. I remember trying to build one 8 bucket back in the day but stopped because of some space issues. I just want simple 2 buckets and a tote. And the top drip or feed line directly to roots. Any tutorials that are simple DIY would be greatly appreciate. Sorry if I'm off
Topic and or hijacked a little

D350 said:

After 2 years battling root rot, I compiled some knowledge about "sterile" RDWC growing. Please, feel free to correct me.
Please, no "get a chiller, temps are high, more oxygen etc." comments. I have perfected everything, even overkilled ALL technical aspects already.
Using tea for last 4-5 grows and still got problems. And I did my homework about the tea and exhausted all possibilities, even adding it daily at stupid amounts. It did help some, though.

So, here is my "sterile" findings:

-Using Chlorine(bleach) or H2o2 is USELESS without ORP/redox meter AND some sort of automatisation to hold your target levels. ORP levels (in mV) tell you how much of your disinfectant is actually doing the dissinfection.
Example: I have put bleach in my infected system, calculated amount to reach about 2ppm. After 1min there was NO active chlorine in the system. Ended using 50x(yes!) the calculated amount to reach 2ppm!!!! And currently still using 5-10x the amount to correct the levels. Here is the answer, why many people claim, that bleach/h2o2 does not work.

- OPR/Redox potential in mV used for dissinfection is from 420mV-800+mV. Beware, colerration betwen mV and ppm of active chlorine is heavily depended on pH!
700+mV will kill everything, but hopefully not your plants. at least 500+ is reccomended for keeping the res clean.

-In case of using Physan (or hydro-fungicide - I think it is very similar) does not produce any ORP levels. Basically you are adding it blindly. (You shold add it every 3-7 days)

- Using pool shock is I think better, as it is calcium compound vs the normal bleach, which is Natrium based.


SO HERE IS MY PLAN:
- I bought the ORP controller on ebay (careful, some have very limited range of control)
- I plan to run the system with pool shock, stable at around 650mV, which is about 0,5ppm at pH 6.
- occasionaly will shock the system with 1,5ppm active Chlorine (around 800mV)

-Thinking of running my 2nd system with physan, 1ml/10gal every 3-4 days to compare.

Any thoughts, comments, questions?

Thank you!

Click to expand...

First of all DWC is complete shit for growing if you are not able to provide constant ac to the area where your growing. If you have rot you have some nasty stuff going on due to hot rez temps period. I am not going to recommend building a rez chiller only going to tell you all I use SWC for keeping moms and clones fresh out of the cutting chamber ONLY.

Hydroton EBB DRIP is the only way to FLY for FLOWERING! No heat problems and ONLY bright white roots all around talking root bound in hydro!

IF YOU DOUBT GOOGLE icmag is boring as shit and see what SoQuick has to say about DAT!