Flooded Tubes vs Undercurrent

[Malevolence]

I've been thinking about flooded tubes, and for that and NFT a lot of people use 4" PVC... wouldn't the root ball easily fill up and clog a 4" pipe? In DWC the root ball gets the size of a soccer ball with a few weeks veg.

I am thinking about running two vertical lamps with 5 or 6 sites around each lamp, for a total of 10 - 12 plants. How would growth speed compare to undercurrent DWC? Could a 4" flooded tube handle plants the same size as a 4' - 5' (untrained) plant in a 2 gallon coco hempy? I don't think I can risk a 50 gallon flood in my apartment from a bucket/uniseal failing.

 

[redi jedi]

NFT is really best suited to growing small plants (SOG) where DWC/RDWC is intended for large plants.

I would imagine growth rates would be similar but cant say for sure.

 

[Malevolence]

I am vegging 2 weeks in DWC cloner/vegger and end up with 4' plants about 2.5' diameter maybe... with no training which ends up being a pretty decent size for this setup I think. The question is can flooded tubes mimic undercurrent, and what size pipes are needed to handle roots of a plant that size. I would also consider horizontal SoG, but I'm not sure which would be better.

 

[hammer21]

If you decide on the tubes use egg crate wrapped in silk screen lay in the bottom of the tubes this prevents water dams and great drainage also I would recommend spraying.

 

[redi jedi]

I would say flooded tube does mimic undercurrent, but I foresee having issues with flow. Creating a drainage channel like hammer21 mentioned may solve this but I would suggest using 6" pipe or better. Or just go undercurrent. I have been using the pool shock method to sterilize and it works very well for me. Very economical too.

 

[Malevolence]

I have tried converting to undercurrent before, but I could not get the 2" uniseals and 5 gallon buckets water tight. I spend a shit ton of money trying different buckets and seals... completely bought out the local supply of underwater jb weld at walmart and home depot. The whole process was struggling with uniseals and trying to sop up leaking water with soggy towels.

And then a quick google of uniseal leak comes up with this thread talking about all kinds of shit https://www.thcfarmer.com/community/threads/do-uniseals-leak-after-a-while.26230/

That's why I was thinking about flooded tubes. I would probably get some big pipes. The PVC tubes would have dams built-in with adjustable height even. Say I were to use 10" PVC pipe, I could set the damn to flood the tube 6" high, and it would be like undercurrent DWC (or so I hope).

Here is the most famous example, but I do not plan on a multi-tiered stadium setup: https://www.rollitup.org/hydroponics-aeroponics/149998-heaths-flooded-tube-vertical.html

Here is a link to the harvest... he's claiming 46oz with a 600w HPS which works out to around 2.15 gpw https://www.rollitup.org/hydroponics-aeroponics/149998-heaths-flooded-tube-vertical-6.html#post2278969

 

[Sativied]

I got 3 plants per 4 feet of a 5inch pipe that get 90% filled with roots (about a month vegging from seed), the other 10% are small rootless areas around the sprayers (planned on LP aero). My plants were 4-6 feet first round I did in tubes. Last round I made an effort (LST) to keep'm at 2-3 feet.

I don't think you would notice a difference in veg speed if you were to try out both. The key with hydroponics that recirculate is to circulate it fast enough, which is obviously easier in large tubes where the roots of multiple plants become a single mass than in separate buckets.

Check my journal in sig below for my second flooded tubes run. Going to make some changes to it soon, which is mostly widening the return pipes so I have a little more space for roots. As it is they end up growing all the way from the tubes into my rez (in which I run air pumps to optimize aeration, though the return waterfalls, including of my chiller, by itself does fine).

wouldn't the root ball easily fill up and clog a 4" pipe?

There's no root ball in flooded tubes, it's root cylinder. Length is more important than diameter.


Vert growing...

 

[powerslide]

Sativied, are your tubes truely "flooded" or just a film at the bottom? I'm building a drip/NFT system to run vertical. I just left the end open last time and roots were only about 1/2 thick on the bottom. If i can figure out how to put my thread in my sig like you did that would be handy dandy, but mine is just a stinkbud deal but top drip instead of sprayers.

I got 3 plants per 4 feet of a 5inch pipe that get 90% filled with roots (about a month vegging from seed), the other 10% are small rootless areas around the sprayers (planned on LP aero). My plants were 4-6 feet first round I did in tubes. Last round I made an effort (LST) to keep'm at 2-3 feet.

Mal, i have 5x5 square tubes i got from lowes, they were on sale half price just a couple days ago. The 5x5 ones are tougher to find, 3 stores in my area and only one carries them, most stores carry the 4x4 square.

I don't think you would notice a difference in veg speed if you were to try out both. The key with hydroponics that recirculate is to circulate it fast enough, which is obviously easier in large tubes where the roots of multiple plants become a single mass than in separate buckets.

Check my journal in sig below for my second flooded tubes run. Going to make some changes to it soon, which is mostly widening the return pipes so I have a little more space for roots. As it is they end up growing all the way from the tubes into my rez (in which I run air pumps to optimize aeration, though the return waterfalls, including of my chiller, by itself does fine).


There's no root ball in flooded tubes, it's root cylinder. Length is more important than diameter.


Vert growing...

 

[powerslide]

See if this works...

 

[Sativied]

Sativied, are your tubes truly "flooded" or just a film at the bottom?

They are truly flooded, as in multiple inches. I use elbow at the end to extend the tubes a bit for extra root space, which is slighting leaning and creates... well, see for yourself:
View attachment 2730452

In the long/straight end of the tubes the flow is about 2.5 inches deep, just below the bottom of the net cups, same as in my preveg DWC box (so no transplant stress...).

Just checked your journal, that's a nice setup you're building, looks more like a half-pipe if you'd put some trays on the floor as well (and leave the bulbs horizontal). Anywya, good luck.

but mine is just a stinkbud deal but top drip instead of sprayers.

I use sprayers solely because I was planning on going low pressure aero, in my new system no sprayers will be includes. One concern I'd have with top drip is the amount of flow. Google for Deep Flow Technique (basically includes flooded tubes) for solid info and examples.

 

[Malevolence]

Those are some serious roots. Are you going to stick with 4"? Seems like 6" would work a little better just judging from pics.

 

[bird mcbride]

The pipe thing is seventies technology. We did the stadium grow. Be prepared for a flood. That's why why we abandoned it, and other reasons.

 

[Sativied]

Those are some serious roots. Are you going to stick with 4"? Seems like 6" would work a little better just judging from pics.

They are 110mm, which is 4.4" roughly. 6 inch would be overkill in my case. As I sort of mentioned in my previous post, the elbows at the end are slightly tilted downwards, which is why they are filled to the top at the end, that is not the case in the rest of the tubes in which the root mass forms half a tube. It depends a lot on the of number of plants combined with veg period. Basically the longer you veg the thicker the pipes need to be.

That said, I'm working on my next setup in which the role of the tubes and the rez is sort of reversed, a little like a Kyowa hyponica 501 system (think DWC but circulation+return waterfall instead of air pump+stones). Basically more root space, but that's primarily because I want to grow more plants and not because of a limitation in my current tubes.

The pipe thing is seventies technology. We did the stadium grow. Be prepared for a flood. That's why why we abandoned it, and other reasons.

Wing technology is much older yet we still fly with and constantly refine it.... sounds like you are dissing a 'pipe thing' because it didn't work for you. I don't know who the 'we' is and what exactly you mean by pipe thing, but DFT is extremely suitable for cannabis and widely used in the greenhouse industry to produce food for hundreds of millions of people (albeit often with square/rectangular trays rather than tubes).

I agree one has to be prepared for a flood, but that goes for growing hydroponics in general. I prepared by using pond foil to turn the bottom of my grow closet into a backup reservoir.

 

[skunkd0c]

NFT is really best suited to growing small plants (SOG) where DWC/RDWC is intended for large plants.

I would imagine growth rates would be similar but cant say for sure.

NFT works very well with larger plants but this is system design dependent
many of the tube/pipe systems are designed for small plants and have very narrow channels

the NFT tray/multiduct systems would be better than the pipe systems for large plants
and generally better overall
as the water will run along a much wider flat shallow channeled surface it has a much larger surface area to spread roots out
also being flat the channel will stay shallow .5cm or less deep the groves cut within the bottom of the channel ensure water can flow under roots
without creating puddles

dwc can grow large plants too, although NFT will get them bigger imo
dwc will work well with small plants sog

This haze plant below grown in a 20 liter NFT tray yielded 21.5 oz (600g)
it was 7 ft wide 5ft high needed 3x 600w to cover it

peace

 

[Sativied]

Skunk dude... you know those pictures don't mean much by themselves... strain, light and other conditions had a much larger influence on those results. I also doubt you are really growing NFT, which is simply not doable with cannabis plants as there are too many roots to cover in a 'film'.

NFT is really best suited to growing small plants (SOG) where DWC/RDWC is intended for large plants.

Hence DFT...

 

[skunkd0c]

Skunk dude... you know those pictures don't mean much by themselves... strain, light and other conditions had a much larger influence on those results. I also doubt you are really growing NFT, which is simply not doable with cannabis plants as there are too many roots to cover in a 'film'.

Hence DFT...

The picture illustrates that large plants can be grown in NFT that is all, of course those other factors you mention have an influence on the results, that is stating the obvious

the system the plant was grown in was a NFT system, the roots were covered with a nutrient film the pump was always pumping
you are perhaps splitting hairs or simply mistaken

http://www.nutriculture.com/nft.html < see where it says NFT

 

[skunkd0c]

I think sativied misinterpreted my post, i was in no way stating that the size of the plant posted was directly attributed to NFT
i was showing that NFT systems can host large plants (depending on design)

if the exact same plant was grown in dwc would it of got the same size or similar size, i would asume it would
aslong as the system had enough space to accommodate the roots

if the same plant had grown in a narrow channel pipe/duct NFT system i think it may of had problems

NFT systems do not produce a large amount of roots imo, when grown with spreader mat the root system is compacted into a fiberglass mat
the spreader mat can also be used to train the roots to grow in the direction of choice
the larger systems that are 7ft or so long or 1m2 can accommodate very large plants as the roots have a huge space to spread out in all directions
the larger the surface the more of the rootmat can be kept out of the water stream, although i havent found this makes too much difference overall
the nutrient film can be seen floating allover the surface of the water it breaks up into small chunks that are around a few inches
these chunks flow allover the roots, you will see little air bubbles around the roots that interact with the film

the British guy that discovered NFT set pretty precise guidelines for it to be true NFT , pump must flow constantly
the depth of stream, the flow rate, the angle of the slope , if these things are not matched exactly and you like to split hairs
you perhaps have a valid point

i have experimented with raising the slope putting pumps on timers, using air pumps all of these modifications would turn the system into a non official NFT system
i found these modifications did not improve the system, and that the system can be run as sold, its common for folk to think these nft systems need air pumps
but they are not needed, the motion of the running water and the fact its shallow when it passes over the roots supplies good levels of oxygen to cause very fast growth

peace

 

[Sativied]

The size of a single plant is rather irrelevant without the total number of plants and root mass for a given space and system light and yield and strain. Like I said, many more factors. Let me put it this way: if something is bigger, it's not an opinion (as you mentioned 'imo') but a matter of measuring. Which you haven't done, so the pics mean nothing. Of course, you can have an opinion about that too. I prefer to stick to the facts.

you are perhaps splitting hairs or simply mistaken

http://www.nutriculture.com/nft.html < see where it says NFT

Perhaps yeah, for trollitup being accurate is considered splitting hairs. Definitely not mistaken either but NFT is a UK invention so I can see why ya'll still call it NFT while it is technically no longer an NFT if the flow is several inches deep and no longer a thin film and therefore no longer providing the benefit of a true NFT system (aeration regardless of the amount of circulation and /or airpumps...), it's dft.

*School's open*
There are multiple ways to differentiate between different hydroponic systems (meaning systems where the only medium is the propagation medium and the roots are in direct contact with the nutrient solution), one of those ways is NFT vs DFT. Another is static vs circulation (and dtw). DWC is static, RDWC is circulation. DWC because it being static needs aeration from airstones. More and more grower start to realize you don't need bubbles if you circulate fast enough. RDWC is essentially evolving DWC towards DFT. A previous poster who posted that about it being from the seventies is merely parroting one of the first google results that show up hen you search for dft. It's the principal that is used, not a particular setup someone labeled DFT. Whether you use tubes, trays or a a square table like I'm building is irrelevant. This is also the reason why tubes aren't suitable for NFT, the non-flat surface on the inside does not allow for a film.
*School's out*

While many people in cannabis forums are discussing semantics and labeling there own systems they are all based on just a few well-know, highly documented, tested techniques used in more professional industries (non-cannabis that is). NFT is misleading for new growers but if you want to call your system an NFT I'd say go for it. Just look at all the "Hempy" style growers (Hempy basically being known as Dutch Bucket / BATO buckets system for decades...).

 

[bird mcbride]

.
A previous poster who posted that about it being from the seventies is merely parroting one of the first google results that show up hen you search for dft....).

Sorry guys but the only googling I do is for spelling. I broke into a lumber yard as a boy in 1972 and that's the first time I seen a mj grow-op and it was pipes. So even though I can only go back to 1972 with this I'm sure it must have been out in the sixties. The other growers brought the system(amonst many) in to compete against my flood and drain tables in 1995. After all the experiments it's flood and drain all the way. The last time(2000) I was in buddies grow room that tried to sell the stadium pipe(or trough) system, was running three flood and drain tables so...

 

[Malevolence]

My goal is to set up an automated recirculating system that doesn't leak and has a low probability of flooding my closet. I love the idea of lining the room with pond liner to contain a flood. I have been thinking about the ideal design for my setup, which needs to be simple and stealth. The flower closet will most likely run off one 15A 120V circuit with two 400w HIDs. I will have a small mom/clone/veg area in another room on a different circuit with a 250w MH, so I plan to veg rooted clones and seedlings about 2 weeks which I have found produces around 2' 6" - 3' plants for me. Plenty of room for 12 plants in flower.

My ideal system would be ucdwc, but I still haven't figured out a good alternative to 2" pvc and uniseals.

DFT with 4" - 6" pvc would be just as well, but I am not sure how I would set up the pipes and plumbing. Seems like it would have to zig-zag in a downward slope or something.

I don't think I am interested in any other methods right now such as ebb and flow, nft, aero, etc.