Wise and knowledgeable expert advise for DWC at altitude.

IamN2pot · Jan 1, 2023

Couple years ago I was toying around with DWC and Kratky, and as I knew nothing about them I started out with leafy green veggies and GH nutes. Yep, kale, spinich, lettus, basil and cilantro. The DWC easily won out. I didn't want to make major mistakes starting off with $25.ea cuttings of cannabis, so I did regular veggies. Talk about weird looks in the grow store when I started asking about nutes for basil. I'm in Colorado, LOL!!! Anyway, after some real success with the veggie DWC garden, I started my cannabis cutting in DWC. You can see both the veggies and the cutting in the picture below. So for the cutting I started using a line of nutes that I won't name, but are local from here in Colorado, and in one of the bottles were solid pieces. The phone # was listed, so I called. The advise I got stopped me in my tracts. I was first ask what kind of hydro system, so I told him DWC. He told me that I could/should strain out the solids and it would/should work fine. Then he ask where I had purchased my DWC and named a manufacturer, "X" in Cal. I said nope, I made it myself. He said that "X" had done a commercial trial of DWC in Denver and it didn't work. Reason was "because of the altitude", the water couldn't hold enough oxygen. I was in the early stages and it was easy to transplant them into soil and that's exactly what I did. No need to beat my head against a wall, I knew dirt works, LOL!!!

Now it's 2 years later and I've been given some conflicting advise. At 4700' I am slightly lower, than Denver, but only 500'? Is that enough to really make a differance? I understand a tiny bit about how a chiller/cooler can help as well as adding Hydrogen Peroxide I'm told can raise the oxygen saturation level, but is that enough??? Help! Is it a general waste of time to do a DWC at altitudes over 2500'-3000' as was suggested to my by the nute manufacturer?

Thanks for your input.

Zill · Jan 1, 2023

N2,

Question…what is the altitude your vegetables growing at?

Zill.

Zill · Jan 1, 2023

N2,

Run from the guy you were talking to.

Altitude to Oxygen Chart - Oxygen Levels at Different Altitudes

Altitude to Oxygen Chart displaying the levels of oxygen in the air at high altitudes. Use this altitude to oxygen chart to determine oxygen levels at altitude.

milehightraining.com

Zill.

IamN2pot · Jan 1, 2023

Zill said:
N2,

Question…what is the altitude your vegetables growing at?

Zill.

That's sort of what I was thinking, but I know nothing about how oxygen levels in the water effect growth. Temps either for that matter. My local grow store uses Hydrogen Peroxide, but no chiller and to be honest, my soil looks better than their DWC. I never added anything but RO and GH nutes to the veggies. Well, almost never. I wanted to experiment with our Chlorimine water supply. I litterly watched the lettus wilt and 30 minutes later the lettuce roots were a rusty red color. Better learned on lettuce than cannabis...

2Bad · Jan 2, 2023

@Moe.Red does DWC not sure about altitude though.

Moe.Red · Jan 2, 2023

Here is my no research reply based on what I know about hydro and DO levels:

Assuming you are keeping the water oxygenated via bubbling or similar, the change in growth rates should be the same for dirt and hydro at the same elevation.

O2 to the roots is necessary in both soil and hydro, in the same proportions.

At altitude you will not get the same growth rate as sea level, but true of soil and hydro equally.

I see no reason hydro at 4000ft. would not work equally as well as soil does at that elevation.

SweetLeafGrow · Jan 2, 2023

IamN2pot said:
hat's sort of what I was thinking, but I know nothing about how oxygen levels in the water effect growth. Temps either for that matter. My local grow store uses Hydrogen Peroxide, but no chiller and to be honest, my soil looks better than their DWC. I never added anything but RO and GH nutes to the veggies. Well, almost never. I wanted to experiment with our Chlorimine water supply. I litterly watched the lettus wilt and 30 minutes later the lettuce roots were a rusty red color. Better learned on lettuce than cannabis...

Keep in mind that there are two ways of running hydro, live and sterile. Sounds like your grow store is running sterile because of the H2O2....kills all bacteria both good and bad. Live hydro utilizes a more natural approach with live bacteria. Thing is with live, you got good bacteria (friends) and bad bacteria (enemies) and the trick is to help the good so that it will overpower the bad. Good likes cooler water, bad not so much. So in a live system you want to run a chiller, you can get away without it running sterile.

Oxygen levels in the water greatly affect growth, one reason hydro is so effective. Water temps also matter, the warmer, the better the plant likes it but the trade off is that the bad bacteria also like the warmer water temps. Ideally I try to run my water temps at 68F.

I used to live in Greeley and I have a friend who had great success with hydro. Greeley is not that much lower in elevation than Denver.

IamN2pot · Jan 3, 2023

SweetLeafGrow said:
Keep in mind that there are two ways of running hydro, live and sterile. Sounds like your grow store is running sterile because of the H2O2....kills all bacteria both good and bad. Live hydro utilizes a more natural approach with live bacteria. Thing is with live, you got good bacteria (friends) and bad bacteria (enemies) and the trick is to help the good so that it will overpower the bad. Good likes cooler water, bad not so much. So in a live system you want to run a chiller, you can get away without it running sterile.

Oxygen levels in the water greatly affect growth, one reason hydro is so effective. Water temps also matter, the warmer, the better the plant likes it but the trade off is that the bad bacteria also like the warmer water temps. Ideally I try to run my water temps at 68F.

I used to live in Greeley and I have a friend who had great success with hydro. Greeley is not that much lower in elevation than Denver.

Thanks for the info. I know there are alot of "hydro" growers around here, but not "true" hydro. They plant in peat and water with "hydro" nutes. That's the route I went for a couple grows as well, but decided to go back to more of a "supersoil" JAWS method (Just Add Water Stupid ). IDK, DWC may be even more involved than the peat/hydro was? Oh, to me 'hydro' is DWC, flood and drain, and variations of them without organic (peat or coco) base for the roots. Does that make DWC a 'steril' method? With those veggies, it was just pH'ed RO with GH nutes on a 20-40 gal rated aquarium pump with 2 stones per tote. Changed water every 7 days and harvested regularly. The pictures were taken in July and I keep the house at 78* in the summer. I have no idea what water temps were.
Thanks for your advice and experiance, @Moe.Red and @SweetLeafGrow

smokedareefer · Jan 3, 2023

IamN2pot said:
Thanks for the info. I know there are alot of "hydro" growers around here, but not "true" hydro. They plant in peat and water with "hydro" nutes. That's the route I went for a couple grows as well, but decided to go back to more of a "supersoil" JAWS method (Just Add Water Stupid ). IDK, DWC may be even more involved than the peat/hydro was? Oh, to me 'hydro' is DWC, flood and drain, and variations of them without organic (peat or coco) base for the roots. Does that make DWC a 'steril' method? With those veggies, it was just pH'ed RO with GH nutes on a 20-40 gal rated aquarium pump with 2 stones per tote. Changed water every 7 days and harvested regularly. The pictures were taken in July and I keep the house at 78* in the summer. I have no idea what water temps were.
Thanks for your advice and experiance, @Moe.Red and @SweetLeafGrow

What exactly would call "true" hydro, pls explain.

Moe.Red · Jan 3, 2023

@smokedareefer , this appears to be the definition being used:

IamN2pot said:
Oh, to me 'hydro' is DWC, flood and drain, and variations of them without organic (peat or coco) base for the roots.

IamN2pot said:
Does that make DWC a 'steril' method?

DWC can be either sterile, live, or neither.

Sterile means you are using H2O2 (peroxide) or similar to kill all bacteria and fungi in the water.
Live means you are inoculating your system with helpful lifeforms that have evolved to be symbiotic with cannabis. Example Great White from the grow shop.
Neither means you are so damn good at growing that you laugh at things like Pythium, and use neither H2O2 or Great White.

The last one is not recommended for new growers, but is quite often what they unknowingly do leading to all kinds of root problems.

IamN2pot · Jan 3, 2023

Moe.Red said:
DWC can be either sterile, live, or neither.

Sterile means you are using H2O2 (peroxide) or similar to kill all bacteria and fungi in the water.
Live means you are inoculating your system with helpful lifeforms that have evolved to be symbiotic with cannabis. Example Great White from the grow shop.
Neither means you are so damn good at growing that you laugh at things like Pythium, and use neither H2O2 or Great White.

The last one is not recommended for new growers, but is quite often what they unknowingly do leading to all kinds of root problems.

THanks for the explaination. That helps alot! ...and as previously stated, I would fit right into that last 'unknowingly' group of newbs, I likely just didn't keep at it long enough to have many root issues. After nearly killing the arugula with my city tap water..., I wanted to see if our Chloramine water would be good after 4 days of sitting. Within minutes the letuce was wilting, literally and the roots turned orange. Needless to say, I've been using a catalytic activated carbon filter as well doing my pH down with L-ascorbic acid (vitamine C) for my supersoil JAWS grows ever since.

Anyway, from the experiance and knowlwdge here, it looks like I should be relatively fine doing DWC and any issues won't really be from a lack of oxygen to the roots, as long as I'm aerifying well and constantly. Is there any advantage to an air pump and stone verses a circulating water pump with venturi?

Moe.Red · Jan 3, 2023

IamN2pot said:
THanks for the explaination. That helps alot! ...and as previously stated, I would fit right into that last 'unknowingly' group of newbs, I likely just didn't keep at it long enough to have many root issues. After nearly killing the arugula with my city tap water..., I wanted to see if our Chloramine water would be good after 4 days of sitting. Within minutes the letuce was wilting, literally and the roots turned orange. Needless to say, I've been using a catalytic activated carbon filter as well doing my pH down with L-ascorbic acid (vitamine C) for my supersoil JAWS grows ever since.

Anyway, from the experiance and knowlwdge here, it looks like I should be relatively fine doing DWC and any issues won't really be from a lack of oxygen to the roots, as long as I'm aerifying well and constantly. Is there any advantage to an air pump and stone verses a circulating water pump with venturi?

No problem.

Not sure if you are aware but lots of massive lettuce farms use hydro. It can be done, and when done correctly is highly efficent.

Cannabis is very different, but it does just fine with nothing but water or fog touching the roots.

For aeration, what you are looking for primarily is moving water from the bottom of the res up to the surface where oxygenation takes place. There is a small amount of O2 that gets dissolved in the water from bubbles, but to be effective they need to be very small, smaller than airstones will make them. So what you get is constant turning of the water and oxygenation at the surface.

Venturis are not one thing. In order for a Venturi to be good at oxygenation, there needs to be a compressive force. Compressed air is very good at oxygenation. It's a Henry's Law thing.

This type of venturi

Does not oxygenate any more than a normal pump would via stirring the water to get new water to the surface. There is no compression of the air it sucks in.

This type

Will, because the orange pipe has a little bend in it at the bottom that creates a high pressure zone, then a tube to hold the air / water mixture together for a short time, providing oxygenation.

Be careful when selecting your hardware and you will be fine.

Moe.Red · Jan 3, 2023

One more thing. I run a live system and recommend anyone doing this do the same, but if you decide to go sterile, the H2O2 will actually break down to O2 and provide oxygenation as it works, so side benefit.

The reason that I go live is because of exudates.

Revealing Root Exudates

While growers often focus on the visible portion of their plants—the stems, leaves, flower

www.maximumyield.com

The plant has evolved over millennia to work symbiotically with bacteria and fungi. Certain fungi will actually make more root area the plant can use. Exudates from the plant are it's way of communicating with the other lifeforms, changing PH, telling them plant conditions, if under attack sending out the help signal... going with sterile removes all that plant activity from the equation completely. To me that is like cutting off your ears because it's just easier to use your eyes.

IamN2pot · Jan 3, 2023

Moe.Red said:
...that is like cutting off your ears because it's just easier to use your eyes.

ROFL!!!!

Thanks, advice taken!
...and thanks for the link, it's a good read for me,

IamN2pot · Jan 3, 2023

LOL, @Moe.Red , I found the venturi assembly on Amazon, but what size submersable for a single 5gal bucket. Looks like they come in sizes from around 350GPH to infinity and beyond!!!! Can you have to much circulation with a larger submersible? damage roots?

Moe.Red · Jan 3, 2023

IamN2pot said:
LOL, @Moe.Red , I found the venturi assembly on Amazon, but what size submersable for a single 5gal bucket. Looks like they come in sizes from around 350GPH to infinity and beyond!!!! Can you have to much circulation with a larger submersible? damage roots?

For a single 5 gal, I don't think a venturi is a good fit.

I'd go with a small diaphragm pump and an airstone or 2. Less power, less noise, less space, and we are only talking about 3.5 gallons of water.

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That one is about as small as you want to go but should work just fine.

Deadstill · Jan 3, 2023

First of all, not to be rude or anything but being the "Mr. Technical" that I am, this is sort of a pet peeve of mine - Altitude is in reference to a plane or being off the ground. Elevation is when you're on the ground (lots of folks get these confused) lol

At any rate I, too, grow in Colorado and I'm at a higher elevation than Denver. While there may be some slight difference in the O2 content of water at different elevations, I highly doubt it's enough to make or notice a difference in a DWC system. I prefer NFT for my hydroponics systems and have never had an issue. If anything, add a decent air pump/stone to your reservoir if you don't have one already, and it should be fine.

One tip I always like to recommend is to try to keep your air pump outside of your grow room or tent. This way you're not circulating any CO2 into your res. Keep your air pump somewhere where it can get fresh air, and run the lines into your grow room accordingly.

But no, in my experience growing at both sea level and over 6,000 feet elevation, I cannot say that I have noticed any difference in growth nor do I adjust my nutrients differently. I do notice, however, outdoor growing at 6,000 feet, the sun gets INTENSE and a shade cloth is *almost* necessary. At this elevation there is less atmosphere to protect from UV, etc.. So we tend to get sunburned faster, cars get hotter, faster, than at sea level. So plants can take it, but I usually try to throw a shade cloth over my outdoor grows (although most of them are too big) and the plants thrive.

This is all just in my experience and I'm not saying anything is set in stone, for everyone has a different style and/or opinion so take it for what it's worth, but I wouldn't worry too much about it, personally.

Hope this helps!

Moe.Red · Jan 3, 2023

Deadstill said:
First of all, not to be rude or anything but being the "Mr. Technical" that I am, this is sort of a pet peeve of mine - Altitude is in reference to a plane or being off the ground. Elevation is when you're on the ground (lots of folks get these confused) lol

At any rate I, too, grow in Colorado and I'm at a higher elevation than Denver. While there may be some slight difference in the O2 content of water at different elevations, I highly doubt it's enough to make or notice a difference in a DWC system. I prefer NFT for my hydroponics systems and have never had an issue. If anything, add a decent air pump/stone to your reservoir if you don't have one already, and it should be fine.

One tip I always like to recommend is to try to keep your air pump outside of your grow room or tent. This way you're not circulating any CO2 into your res. Keep your air pump somewhere where it can get fresh air, and run the lines into your grow room accordingly.

But no, in my experience growing at both sea level and over 6,000 feet elevation, I cannot say that I have noticed any difference in growth nor do I adjust my nutrients differently. I do notice, however, outdoor growing at 6,000 feet, the sun gets INTENSE and a shade cloth is *almost* necessary. At this elevation there is less atmosphere to protect from UV, etc.. So we tend to get sunburned faster, cars get hotter, faster, than at sea level. So plants can take it, but I usually try to throw a shade cloth over my outdoor grows (although most of them are too big) and the plants thrive.

This is all just in my experience and I'm not saying anything is set in stone, for everyone has a different style and/or opinion so take it for what it's worth, but I wouldn't worry too much about it, personally.

Hope this helps!

Hey deadstill how’s things haven’t seen you around for a minute.

Biggest difference to us at elevation is that blowers are less efficient because the air is thinner

Deadstill · Jan 3, 2023

Moe.Red said:
Hey deadstill how’s things haven’t seen you around for a minute.

Biggest difference to us at elevation is that blowers are less efficient because the air is thinner

Good man just took a break from the Farm for a little while due to being busy with real life stuff but things finally slowing down a little for the winter. Although I'm still busy making preparations for next year's crops, now I have time to breathe without all the red tape, paperwork, and bureaucracies to deal with.

Seriously though, I don't know which is more work. Actually growing the industrial hemp, or jumping through all the damn hoops, reporting to 3 different agencies, etc. just to grow a damn crop...

I am extremely irritated by the inadaquecies and incompetence of the Colorado Springs Farm Service Agency. It took them 6 months just to issue me a damn Farm Number, which I have to have to even SELL my crop from LAST year...

At any rate all is good here! Just trying to stay warm LOL

Moe.Red · Jan 3, 2023

Yeah the hemp thing seems sketchy. Lots of pitfalls for sure. 1diesel1 had a tough time too up in Oregon.

Seems like a tough way to make a living.

Wise and knowledgeable expert advise for DWC at altitude.

Wise and knowledgeable expert advise for DWC at altitude.

IamN2pot

Zill

Zill

Altitude to Oxygen Chart - Oxygen Levels at Different Altitudes

IamN2pot

2Bad

Moe.Red

SweetLeafGrow

IamN2pot

smokedareefer

Moe.Red

IamN2pot

Moe.Red

Moe.Red

Revealing Root Exudates

IamN2pot

IamN2pot

Moe.Red

Amazon.com: REDGO Slient 2 Air Bubble Disk Stone Aerator Aquarium Fish Tank Pond Pump Hydroponic Oxygen with 2M Silicone Tube : Pet Supplies

Deadstill

Have Dick, Will Travel

Moe.Red

Deadstill

Have Dick, Will Travel

Moe.Red

Wise and knowledgeable expert advise for DWC at altitude.

Wise and knowledgeable expert advise for DWC at altitude.

IamN2pot

Zill

Zill

Altitude to Oxygen Chart - Oxygen Levels at Different Altitudes

IamN2pot

2Bad

Moe.Red

SweetLeafGrow

IamN2pot

smokedareefer

Moe.Red

IamN2pot

Moe.Red

Moe.Red

Revealing Root Exudates

IamN2pot

IamN2pot

Moe.Red

Amazon.com: REDGO Slient 2 Air Bubble Disk Stone Aerator Aquarium Fish Tank Pond Pump Hydroponic Oxygen with 2M Silicone Tube : Pet Supplies

Deadstill

Have Dick, Will Travel

Moe.Red

Deadstill

Have Dick, Will Travel

Moe.Red

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