Sick of Root Rot can I convert my RDWC to some other system?

Unless you go dirt I'm going to say you will likely have the same issues. Pythium is not temp dependant. It attacks roots at any opportunity. Higher temps only speed up the metabolic and reproductive rates. There is a reason you kept getting it and without finding you will likely have the same issue no matter what type of hydro you do

I do hope you are wrong Aqua but I can see where you are coming from as the reservoir feeding the plants will be the same res the roots were in with the rot. I do think Capn Style creates unfavorable conditions for the rot as opposed to RDWC. I can inoculate the roots directly easily saturate them with beneficial's and create a favorable environment around the roots for the beneficial's.

My main dilemma is using the plants I now have which do have the rot. If 100% of the new roots are not white in the Rockwell I will not use them.

System will be super cleaned with Sodium percarbonate which I have just started using and it is the business as far as I can see.

What is Sodium Percarbonate? - In the UK Sodium percarbonate, also known as Sodium Carbonate Peroxyhydrate, or oxygen bleach powder is a free-flowing, white powder. It is an addition compound of sodium carbonate and hydrogen peroxide. Percarbonate has an active available oxygen content (13%) which is equivalent to 27.5% Hydrogen peroxide. It breaks down to oxygen, water and sodium carbonate upon decomposition. It is an environmentally safe bleaching agent. Sodium Percarbonate / oxygen bleach offers many of the same functional benefits as liquid hydrogen peroxide. It dissolves into water rapidly to release oxygen and provides powerful cleaning, bleaching, stain removal and deodorizing capabilities in addition to being effective at killing bacteria, fungus, viruses and algae. It has the added advantage of having no odour.

Aqua Man said:

Unless you go dirt I'm going to say you will likely have the same issues. Pythium is not temp dependant. It attacks roots at any opportunity. Higher temps only speed up the metabolic and reproductive rates. There is a reason you kept getting it and without finding you will likely have the same issue no matter what type of hydro you do

Click to expand...

The reason that you have less chance with dirt is that the dirt is more like a buffer.
With hydro everything is very direct.
So with hydro you have to make sure that all your circumstances are ok.

For example there are less beneficial bacteria in just water. There is also nothing that the bacteria can hold on to. Just the water and the roots. One of the reasons for fungi like pythium.
Temperature differences can be a cause: When you change your reservoir and the new water is colder then the water you had before. With soil, the soil will keep the same temperature much better.
Lack of oxygen can also be a cause of phytium. Now there is always plenty of DO in your water with almost any hydro system. But the question is: does the water inside the rootball gets refreshed as well? Stagnant water inside a rootball can be a problem. Plenty of DO rich water around the rootball, but inside the rootball it is dead. With soil there is plenty of O in gaseous state (if your are not drowning your roots of course)

Pythium does also occur in soil, cocos, rockwool, etc.
A reason for pythium can be that your EC is too high. Your roots get less defensible.
Also a high temperature of your roots and a low temperature of your plants can help getting pythium infection.
When your root temperature is for example 23 degrees and your plant temperature is lower, this also can be a cause for pythium. In the night a lot of growers have their room temperature below the temperature of their medium.
(I think this is why a lot of people with chillers perhaps have less pythium: Their root temperature is never higher then their room temperature. Many of them think that pythium occurs just by the simple fact that it gets active only above a certain temperature. But Pythium can occur by any temperature, although when you get above 30 degrees it will occur way faster)
I do realize that in nature this situation does also occur in cold nights, but what I am describing is how commercial growers try to avoid pythium.

It is almost never 1 reason: It are several circumstances together. Some spores that were already in your water. Some temperature problems, killing too many beneficial bacteria with H2O2, biofilm in your tubes, lack of oxygen, your EC a bit high, a little bit of this and a little bit of that.

Thanks For this post Keesje Very informative and it has put my mind at rest slightly. Growing Capn Style the roots aren't in the water. The plants are potted up from small pots and when flowering they are in 7 gallon/25 litre pots of mini Rockwell cubes which create a super aerated medium by design. They are top fed twice daily for 15 minutes each time and the nutrients are recirculated then changed weekly.

I had root rot in my very first grow in this the brand new system, as you say caused by a little bit of this and that, mine in particular due to high EC and light leaks rather than high temps. Once it was in there I think it is difficult to eradicate and will rear its ugly mug at any opportunity when your guard is down.

Google up Popular Mechanics ebb and flow system.

It's a complete plan on how to build a cheap, efficient, effective ebb and flow system.

You're welcome.

One should find out what causes the root rot in a certain system.
The article in Popular Mechanics for example says about DWC "you are more liable to get root rot."
They don't explain why.
A system of course can have flaws that make the roots more vulnerable for root rot.
What are those specific reasons in DWC? (if the statement of Popular Mechanics is true of course)

To be honest: I also would never use DWC.
My reasons are:
- Stagnant water in the rootball > not enough O available
- Bringing to much CO2 in the water > pH fluctuation.
- Irritating noise (very personal)
- Stones that need replacement every time.
- Reservoir control and changing is annoying. Easy to hurt roots or give some kind of shock.

@TacoMac I also don't find the Popular Mechanics article very good. It is not bad either, but there are hundreds of video's and sites where you can see a build.
For example: How do you refill the reservoir when the tray is resting on this reservoir? How will you pick up the tray when it is full with plants?
Then: Rockwool and hydro are not always the best combination.
Rockwool gets easily saturated and once the tiny amount of DO is consumed, the water in the rockwool can prevent fresh oxygen to reach the roots. Of course the water will also be consumed by the roots, but it can take some time. And all that time there is no fresh oxygen near the roots.

alot of rdwc growers I read about have ditched airstones and designed a waterfall type return for their setups. because the water does a waterfall it actually makes more dissolved oxygen as well as less heat caused by air pumps/stones

Keesje said:

How do you refill the reservoir when the tray is resting on this reservoir?

Click to expand...

You just pour it in the fucking tray. It drains into the reservoir.

Keesje said:

How will you pick up the tray when it is full with plants?

Click to expand...

If you can't handle 10 pounds of weight, just go ahead and put a bullet in your skull and be done with it.

Wow dude. Seriously? You can't figure that the fuck out?

I'm amazed you remember to breath on your own.

Why so rude?

Ok.
Again: How do you get out the old water then?
Sure you can lift the tray. Pump it out. It can all be done.
But if you want to clean it properly in between, you have to have the tray rested somewhere else.
So a tray seperate from a reservoir would be a better design by Popular Mechanics.

Lifting10 pounds of plants is easy.
But not everybody is a small grower like you perhaps are.
I would not even bother to grow 10 pounds of plants (10 pounds of dried yield, yes, sure)

Besides that, even a small amount of longer plants need sometimes some support, with a net or bamboo sticks or something like that.
Moving them without hurting them every time is just not as easy with a tray that is resting on the reservoir.
There is a reason that commercial or bigger growers are separating their reservoir from the tray.

I guess you disagree, but I just give my point of view from experience.

https://www.rollitup.org/t/i-gotta-lose-the-air-pumps-how-plus-my-awesome-mini-dwc.960807/page-2

check out how he makes each rdwc site bucket have a waterfall, and then the way he sets up the return manifold

Nizza said:

alot of rdwc growers I read about have ditched airstones and designed a waterfall type return for their setups. because the water does a waterfall it actually makes more dissolved oxygen as well as less heat caused by air pumps/stones

Click to expand...

Although I think that a waterfall is a better and easier to build system, I do not agree that it will create more DO.
Having maximum DO is very very easy, with almost every hydro system.

If an airstone pump will create more heat then a pump that you need for a waterfall... I have no idea.
It would be a nice test. I will see if I can make a set up one day.
I gues a pump that creates a waterfall can be a pump with a small wattage.

Just a quick question do I need an air stone in my holding tank, it will be feeding my res when it gets lower as the plants take up the water. The holding tank is 200 litres but I will only fill it to the top if I am on a short vacation.

No, no need for an airstone in your holding tank.
What you can do is have a circulation pump run every hour to keep your nutrients mixed.

200 litres is nice. If you can afford it money wise, always use the 200 litres.
Then the balance between the different elements (calcium etc.) will stay longer the same.
At least that is what I would do. But I have no idea how much you would pay for the exra nutrients.

The pythium species that affect hydro are not the same as in dirt. This is why I say unless you switch or get to the root of the problem it's likely to reoccur. Now that's not to say you switch and it was say the air stones were to aggressive causing root damage and poor health that then was infected and the switch solved your problem is absolutely possible. Or some other variable that changed.

Aqua Man said:

The pythium species that affect hydro are not the same as in dirt.

Click to expand...

True, there are so many, pythium aphanidermatum, ultimum, irregulare, dissotocum are just a few and there are more.
(I did have to look this up )
Commercial growers who can spot the slightest changes in their plant-color, plant form or whatever, can hardly tell one kind of pythium from the other.
They have companies come over who will do DNA-analysis of the water to determine what is causing the root rot.

had to deal with similar root rot problems.
Was quite a pain to keep the DWC alife, even with teas bennies etc.
There are so many factors to take in to account when doing DWC, i fear somehow i would take years of trial and error to master.
This summer i didnt even tried DWC, no chiller in house and went straight for hempys.
So far it looks i made the right decission.
They re quite easy to handle, cost nothing and the results are really good.
Beside the rot problem with DWC, i also like that i am now able again to veg them in small coco pots under low light before transplanting in hempys.
In DWC you have to transplant real early (i cant press a ounce of rootball trough a 2" hole at least), in Hempy, the later the better.
Also, if you run in to problems with your DWC it starts to become lots work, wasnt worth it for me.

I dont say DWC dont work, DWC is great, you just need some luck or tons of equipment.

As far i read and encountered myself, DWC is really prone to rot, other Hydro system are more relaxed in this regard, sure soil is a safe bet as long youre not completly overwatering.
Hempys are quite forgiving in this regard, use 50/50 perlite coco, i ad TNC bennies, sometimes a tea here n there and i use enzymes.
All things which help me with the rot in the DWC, in the hmepys they seem to work even better.
I wont even have fear to pour in sugar or organic stuff, and allready did.

May turrn my hempys in to some recirculating hempys next time, which will make it a... idk.
In the end i would also say, some simple hempys a recirdulating system or ebb n flow hydro system is more relaxed to grow then DWC and give also great results in the end.

Good luck with converting the system and get rid of the rot, to me it looks like youre on the right track.
For sure a heavy use of heisenberg teas will help you even further in your new setup.

Hope they really recover, may take some cuts as safety.

Although I have no proof or numbers, it seems that rootrot occurs more in DWC.
If this is true (which I don't know if it is) what would be the reason?

Some commercial growers don't use DWC or venturi because they say it brings in organic material in their water.
Perhaps this is true, but why wouldn't a waterfall or E&F do the same?

would say the amount of post in the forums telling the story.
rot , 90% with DWC or other water only method.

Reasons? many, i am not willing to try 3 aeration methods to find after 6 moths or so one working for me.

I would also not put my plants to risk. You are absolutely right.

Keesje said:

No, no need for an airstone in your holding tank.
What you can do is have a circulation pump run every hour to keep your nutrients mixed.

200 litres is nice. If you can afford it money wise, always use the 200 litres.
Then the balance between the different elements (calcium etc.) will stay longer the same.
At least that is what I would do. But I have no idea how much you would pay for the exra nutrients.

Click to expand...

Thanks Keesje. Just to confirm my holding tank will just be drip feeding my main system, and I won't need an airstone in there ? or anywhere else for that matter?

My only other concern is keeping the roots from coming out of the bottom of the pots, will they air prune?

I have the recirculating pump running 24/7 but maybe several times a day would suffice? Would the nutes still stay fresh?