First RDWC Grow - Taking the Deep Water Culture Plunge

  • Thread starter SweetLeafGrow
  • Start date
  • Tagged users None
SweetLeafGrow

SweetLeafGrow

Supporter
592
143
Im assuming he was telling you that so you dont get root rot. . cause with root rot. .all nutrients have a hard time. Warmer temps promote root rot is what im guessing he was talking about.
Yes, this was the argument for keeping temps lower. Hit almost 74F in the res last night and it wasn't too hot yesterday in the low 80's. I expect it to get a lot warmer if I don't do something.
 
SweetLeafGrow

SweetLeafGrow

Supporter
592
143
I seen my comment about you running a live system. What room is your airpump in? Whats the temp of the room your air pump and res is in? I have to cool my bedroom with a window unit. Anyways gotta go back inside work
The air pump is in the same room as everything else and the temp currently is 70F in the tent, water in the res is sitting at 69F currently.
 
Moe.Red

Moe.Red

Staff
Supporter
2,742
263
Hey sweetleaf,

I hope the chiller turns out to be necessary, either way nice to have control.

I find that DO is better at lower temps (i.e 68*) but bacteria grows a bit faster at higher temps (i.e. 72*)

EDIT: DO = Dissolved Oxygen in the water. Expressed as a percentage or volume / volume ratio.

DO really helps the plants and combats anaerobic bacteria. I have done some testing and with my airstones I am able to get the DO to about 150% or about 15mL/L range. That is great for BB and plants. So if you really want to tweak this, my results would guide a higher initial temp in the res when first starting because small plants don't use as much O2 and building that colony fast will fight root rot. Then after the colony is fully established, you can bring the temps down with the chiller to the 68 - 70 range for best plant performance.

If you do it right, here is what you have to look forward to:

0FBDE6A6 1974 4F77 B8D4 5B78F9BBAA93



Root mass is approx equal to bud mass, or at least they correlate. So this would be a "big" harvest situation if that is your goal.

EDIT: I keep hearing that nutes stain roots. Not true. H2O2 damages root tissue for the sterile guys, and they interpret that as micros staining. No staining there and these have been fed a full diet sans H2O2.

EDIT EDIT: That gap between the bottom of the net pot and where the root mass starts is the distance below the pot where the water line sits. Hopefully you were able to get yours adjusted down a bit.
 
Last edited:
SweetLeafGrow

SweetLeafGrow

Supporter
592
143
Thanks Moe. Trying to understand what you are saying.

Pardon my ignorance, but what is DO? Also, what is sans H2O2? Is that a typo or did you just mean Hydrogen Peroxide? Are you running sterile?

I see the gap, mine is a bit higher than yours looks but I was worried about getting it too low for those short roots. I'd say it's about 1/2" to 3/4" gap on what I have now and I did notice this morning that some roots are showing out the bottom of the basket, not a lot, but some are def poking their head out. I can let it get lower once roots are down in the water I'm guessing.
 
Cashmeh

Cashmeh

1,605
163
The air pump is in the same room as everything else and the temp currently is 70F in the tent, water in the res is sitting at 69F currently.
Yea keep your temps low since this is also your first rdwc grow. Since your live you wont have issues running in the low 70s as long as you pot is well aerated and no light gets in there.

I average 73f, prolly 74f and my bbs are still able to outpace the pythium. From 68 to 72 the growth rates increase at a noticable rate. Above that its just too hard to manage to even test to see if its worth it. I cant visually see a growth rate increase from 73 to 75. I dont mean to run that warm, I just dont have issues doing it.
 
Cashmeh

Cashmeh

1,605
163
Hey sweetleaf,

I hope the chiller turns out to be necessary, either way nice to have control.

I find that DO is better at lower temps (i.e 68*) but bacteria grows a bit faster at higher temps (i.e. 72*)

DO really helps the plants and combats anaerobic bacteria. I have done some testing and with my airstones I am able to get the DO to about 150% or about 15mL/L range. That is great for BB and plants. So if you really want to tweak this, my results would guide a higher initial temp in the res when first starting because small plants don't use as much O2 and building that colony fast will fight root rot. Then after the colony is fully established, you can bring the temps down with the chiller to the 68 - 70 range for best plant performance.

If you do it right, here is what you have to look forward to:

View attachment 1257127


Root mass is approx equal to bud mass, or at least they correlate. So this would be a "big" harvest situation if that is your goal.

EDIT: I keep hearing that nutes satin roots. Not true. H2O2 damages root tissue for the sterile guys, and they interpret that as micros staining. No staining there and these have been fed a full diet sans H2O2.

EDIT EDIT: That gap between the bottom of the net pot and where the root mass starts is the distance below the pot where the water line sits. Hopefully you were able to get yours adjusted down a bit.
H202 and bbs or am I reading it wrong?
 
Moe.Red

Moe.Red

Staff
Supporter
2,742
263
Thanks Moe. Trying to understand what you are saying.

Pardon my ignorance, but what is DO? Also, what is sans H2O2? Is that a typo or did you just mean Hydrogen Peroxide? Are you running sterile?

I see the gap, mine is a bit higher than yours looks but I was worried about getting it too low for those short roots. I'd say it's about 1/2" to 3/4" gap on what I have now and I did notice this morning that some roots are showing out the bottom of the basket, not a lot, but some are def poking their head out. I can let it get lower once roots are down in the water I'm guessing.
Sometimes my literary purple prose gets in the way of communication.

DO = dissolved Oxygen.

Sans H202 means no H2O2 used. H2O2 is Hydrogen Peroxide. For those coming after, this is what is used by some RDWC growers in place of bacteria and is considered a "sterile" grow.

I am not sterile. If I was, and was running H2O2, those roots would have a red tinge to them which is the H2O2 damaging the epidermis of the root.

As far as the water reaching the roots - it is not necessary when the plants first go in. All those bubbles come up to the surface, pop, and sprinkle the roots continually, even if only an inch long. They will get in that water in short order. It's like aeroponics for a short time until they do. But the other thing you will likely notice is a stall in vertical growth of the plant as the roots grow faster and the rhizosphere develops. Not to worry, often you want to back down the lights for a few days while the roots catch up to the growth above ground.
 
Last edited:
Cashmeh

Cashmeh

1,605
163
Sometimes my literary purple prose gets in the way of communication.

DO = dissolved Oxygen.

Sans H202 means no H2O2 used. H2O2 is Hydrogen Peroxide. For those coming after, this is what is used by some RDWC growers in place of bacteria and is considered a "sterile" grow.

I am not sterile. If I was, and was running H2O2, those roots would have a red tinge to them which is the H2O2 damaging the epidermis of the root.

As far as the water reaching the roots - it is not necessary when the plants first go in. All those bubbles come up to the surface, pop, and sprinkle the roots continually, even if only an inch long. They will get in that water in short order. It's like aeroponics for a short time until they do. But the other thing you will likely notice is a stall in vertical growth of the plant as the roots grow faster and the rhizosphere develops. Not to worry, often you want to back down the lights for a few days while the roots catch up to the growth above ground.
I figured it was due to my lack of understanding. Dumb it down for us next time. I'm actually good at dumbing it down cause im pretty um . . wait. . im just dumb :(
 
SweetLeafGrow

SweetLeafGrow

Supporter
592
143
Thanks for all the clarification Moe! Makes perfect sense for sure. I'm blown away by that root mass, wow. Cash, you are killing it bro and I hope I can be as dumb as you my first go!

This morning roots are coming out all over the bottom of the net basket. The plant looks a bit unhappy to me and I can see a bit of brown on those roots, not a lot but it's def there. Ordered a chiller (that light that was on sale that I was going to get is going to have to wait!) yesterday and found out this morning it's going to be delivered on Thursday sometime, hopefully during the day so I can get it installed immediately. Got a pump ordered for the chiller but I'm unsure what the line sizes are so not sure if they are 3/4" or 1/2" so I can get ready with all the parts. I need to find some 3/4" tubing if it's that size but I have some 1/2" on hand. I'm currently sans 3/4" tubing 🙃

I have to work Thursday night and then again on Friday morning so I have to find the time to get it installed ASAP. Temps are drifting toward 75F at the end of the day and then comes back down toward morning and I am afraid I am headed for disaster if I don't get this fixed right away.
 
Moe.Red

Moe.Red

Staff
Supporter
2,742
263
I'm currently sans 3/4" tubing 🙃

Ahahaha. Now I have to remove sans from my lexicon. Wait, probably need to remove lexicon from my um what was I saying?

what chiller did you get? If the same as mine I can help you with the fittings needed.

Can you show a pic of the brown on the roots? Slimy or smelly?

How is your oxygenation? What air pump / stones are you running and where?

In a pinch just freeze a 2 liter bottle with water in it and put it in the res. If you had 2, you could keep one in the freezer and one in the res and swap out as needed.


Depending on what the roots look like, worst case scenario is you need to run some H2O2 for now to kill off Pythium or whatever you have. You can keep it sterile at that point or go back to live once it is gone and the H2O2 is out of the system.

EDIT: These will help you know when it is safe to put the bacteria back in if you end up going the peroxide route:

 
Last edited:
SweetLeafGrow

SweetLeafGrow

Supporter
592
143
Ahahaha. Now I have to remove sans from my lexicon. Wait, probably need to remove lexicon from my um what was I saying?

what chiller did you get? If the same as mine I can help you with the fittings needed.

Can you show a pic of the brown on the roots? Slimy or smelly?

How is your oxygenation? What air pump / stones are you running and where?

In a pinch just freeze a 2 liter bottle with water in it and put it in the res. If you had 2, you could keep one in the freezer and one in the res and swap out as needed.


Depending on what the roots look like, worst case scenario is you need to run some H2O2 for now to kill off Pythium or whatever you have. You can keep it sterile at that point or go back to live once it is gone and the H2O2 is out of the system.

EDIT: These will help you know when it is safe to put the bacteria back in if you end up going the peroxide route:


Thanks for all the great tips and help Moe.

I picked up this chiller off ebay-

Active Aqua 0.25 HP 396-925 GPH Hydroponic Water Chiller w/ Power Boost (Used)

It's bigger than I need but I had read to get oversized before under, and this was a great deal @ $300 shipped so I went with it. It shouldn't have to work as hard as the 1/10 HP version.

Here is a photo of the roots protruding from the basket.

IMG 0669


Oxygenation as far as I know is good. The air pump I am using is by Active Aqua and it's the 7.8, two output version. I have two air stones in the system, one in the res and at the plant site, which I try to get right under the net basket.

IMG 0671


Not sure I want to do the H202 thing if I can get away with it. I can try the frozen bottle thing for the next couple of days if you think I ought. I'm assuming I will need to remove some of the water that the frozen bottle would displace to keep the water level below the net baskets?
 
Moe.Red

Moe.Red

Staff
Supporter
2,742
263
Yup, I have 2 of that same chiller. Since it is used, hard to say but stock they come with both 3/4 and 1/2 fittings.

Aeration seems fine.

That brown is a bit concerning tho. Once root rot has set in, you unfortunately need to kill it chemically before you can hope to catch up and overpower it with BB. At least that is what I have found. I'm also seeing something on your airstone. Possibly algae. If this is algae and not Pythium you just need to fix the light leaks and it will die once it cannot photosynthesize. I think given your situation, I would try that first by either adding hydroton, coco coir or a cobbled together light block like a plastic plate or something around the plant blocking any light around the net pot and see what it looks like tomorrow. Also try to get the temps down as discussed with ice. If tomorrow it is worse with no light, you may need to nuke it with H2O2. If it is receding, it's algae and continue on with light blocking techniques until it is gone.
 
Cashmeh

Cashmeh

1,605
163
Cover it with a bathtowel or blanket for now. Its a great short term fix. Cut a slit and you can even cover the netpot lol. . i do it.

Even in sterile you try to keep the micron growth down. I mean might as well just take the lid off if you dont wanna cover that net pot. . joking. .dont do that. .
 
20220626 182000 HDR
SweetLeafGrow

SweetLeafGrow

Supporter
592
143
Thanks guys, got that all that done. Water bottles in the freezer now. I'm wondering if it might be helpful to add a bit more Hydroguard during this process.....not going to do that, just wondering out loud. Here is a couple of better photos of that airstone see if it shows one way or the other more clearly. I really don't want to use H202 if I don't have to.

IMG 0673


IMG 0672


Here is everything topside after trying to block the light. I put a bit more hydroton in and then a couple of black socks on top, then some black plastic from a garbage bag on top.

IMG 0674
 
Moe.Red

Moe.Red

Staff
Supporter
2,742
263
That works. Not long term but perfect for today.

If that airstone was sitting with the hose coming up, I'm afraid I'm leaning heavily towards pythium. Algae would not grow more on the area with no light. Sorry man, but I'd have some H2O2 ready I think that is where we are headed. Dammit!
 
Moe.Red

Moe.Red

Staff
Supporter
2,742
263
Here is a little reading material while you wait for your chiller:

 
steamroller

steamroller

848
143
Never seen H202 test strips ?
As far as testing water strips are known to be the least accurate method but a good fall back/ quick check??
My understanding of H2O2 in water is that it converts to water and oxygen with the standard dose of 1-3 ml. per gallon in 12-24 hours .
Does it somehow last longer in grow systems ?
I have used plenty of H2O2 in tanks of water that were anything but sterile. Never had an issue?

I agree the air stone looks contaminated unless it is diatoms that naturally grow in new system until they eat themselves out of house and home. Could be months,but in water the brown 'slime' is not a issue to be concerned with. They do not need light.
I have ZERO hydro experience so maybe it has different meaning, but it could be diatoms also.
 
Moe.Red

Moe.Red

Staff
Supporter
2,742
263
Never seen H202 test strips ?
As far as testing water strips are known to be the least accurate method but a good fall back/ quick check??
My understanding of H2O2 in water is that it converts to water and oxygen with the standard dose of 1-3 ml. per gallon in 12-24 hours .
Does it somehow last longer in grow systems ?
I have used plenty of H2O2 in tanks of water that were anything but sterile. Never had an issue?

I agree the air stone looks contaminated unless it is diatoms that naturally grow in new system until they eat themselves out of house and home. Could be months,but in water the brown 'slime' is not a issue to be concerned with. They do not need light.
I have ZERO hydro experience so maybe it has different meaning, but it could be diatoms also.
The test strips I linked above are what I used to use when I was sterilizing a system. So, harvest done, wanna get all the crap out before you start again, easiest way is peroxide at about 50PPM. Run it like that for a day or 2, then do water changes until there is no peroxide detected on the strip before adding bacteria back in.

1 - 3mL is a very low amount to run sterile hydro.

Yes, it could be diatoms or many other things. But this is how it is supposed to look:


so the question is what is the best course - least destructive course of action going forward.
 
steamroller

steamroller

848
143
I meant diatoms on the air stone not the roots .
The roots I will trust if others say they should not be brown.
But in a non sterile environment diatoms grow until the system is cycled .
Isn't that why you have bio media in your res Moe? To house the proper bacteria.
Low doses of any med [today will be H2O2] only work on a form of life appropriately sized to the amount used .
1-3ml will kill most algae and other single celled life forms without harming larger more developed life.
 

Similar threads

Mcmc631
Replies
1
Views
322
Ponky
Ponky
T
Replies
46
Views
2K
Aqua Man
Aqua Man
B
Replies
0
Views
340
Blazein1
B
B
Replies
30
Views
2K
Electrolights
Electrolights
Cashmeh
Replies
87
Views
4K
Cashmeh
Cashmeh
Top Bottom