Why do people still grow with NFT?

Sativied · Aug 27, 2014

goliath said:
I’m just curious why plants need o2 in the roots? Don’t plants breathe co2 and animals breath o2? Just want to know the factual basis for this.

Plants do produce way more oxygen then they need (allowing us animals to breathe) but they do need some oxygen itself, to turn the sugars created by photosynthesis into energy, to burn fuel sort of speak.

Read this for a layman's explanation:
Respiration

And as you can read in that article, plants do take up oxygen through their leaves as well. Even through stems. The roots take up "in water dissolved oxygen", they do not need to be in contact with 'air'.

Gandalfalfa · Aug 27, 2014

Coir said:
I get $2 a head wholesale for my NFT lettuce. $2.75 a head at the farmers market. Easy to grow, fast turnaround. I think the question is why WOULDN'T people grow this way. Although, I do believe the OP was asking about NFT cannabis rather than lettuce.

Need a lot of space to make it profitable though. With lettuce that is. Cannabis...well everyone has they're preferred methods. :)

Coir · Aug 27, 2014

Gandalfalfa said:
Need a lot of space to make it profitable though. With lettuce that is. Cannabis...well everyone has they're preferred methods. :)

It all depends. I use rain gutters attached to the sides of a 3400sq' greenhouse to grow in and it covers the entire operating cost of the greenhouse each year in what was previously unused space. I consider that profitable.

Captive · Aug 28, 2014

Supercharge said:
Meh..it’s a very reasonable question. Firstly plants don’t ‘breathe’ CO2, they ‘eat’ it - or rather, they ‘fix’ it. Secondly, plants do breathe O2, just like us, they need O2 for oxidative metabolism. The electron transport systems they have for this are functionally the same as ours - mitochondria. In fact plants and humans share roughly 60% genetic homology, mitochondria is just one example of this, which also happens to be an example of the secondary endosymbiosis which led to the evolution of eukaryotes. So contrary to popular belief, the leaves of a plant are not its “lungs”, but rather, its roots are.

i’m a layman and i don’t understand. if you have the time, could you please explain what you mean by ‘eating’ co2? i thought plants ate nutrients, that’s why you give it to them.

20kwDreamer · Aug 28, 2014

I think the issue that NFT isn't very popular anymore so there isn't much progress in the method nowadays. The DO issue is easily resolved with a wooden air-stone in your res and high-pressure top-drip feed lines. Only recent example I can think of is Med-Man tables. I like them because for those folks in states where an oz of medicine or a few plants is still a felony offense it makes setting up a lot more discreet. Bringing in some 2x6 and a few sheets of plywood is low key. A bag of hydroton can do the job for 24x 6" net-pots, rinse and reuse. Off-topic: those same folks might as well run a higher plant count and chop more often - something Med-Man does not do. 9-12 ladies in a 5x5 foot print under a 1000w average 900g and still get an extra crop in a year.

Supercharge · Aug 28, 2014

Captive said:
i’m a layman and i don’t understand. if you have the time, could you please explain what you mean by ‘eating’ co2? i thought plants ate nutrients, that’s why you give it to them.

Sure, happy to help. So that’s another misnomer, and leads to the belief that giving your plants more nutes will result in bigger yields. The vast majority of a plants dry weight is cellulose, and the vast majority of that is carbon. The plants don't get his carbon from the water (H20) or nutes (salts), they get it from the atmosphere in the form of carbon dioxide. Addressing your question on nutes; probably 98% of your nutrient, in concentrated form, is water. If you let 1 liter of Canna Flores evaporate in the sun for a few days you’d be left with just a few grams of crystallized salts. But your yield will have a dry weight (hopefully) measure in pounds, not grams. Where is the weight coming from? Not the water, not the salts, so the air. Plants take in micro and macro nutrients from the ground, because they can’t obtain these things from air. Unlike us they can’t eat a cheeseburger and get half the periodic table in one bite.

goliath · Aug 28, 2014

see what i mean? this guy is a rockstar. i seriously did not know that shit and im not at all proud to admit it.

Supercharge · Aug 31, 2014

Hardly, haha. I just nerd it up. People seem to forget CO2 has weight. When you wake up in the morning you will be a couple of pounds lighter than when you went to bed. Yes, you have lost a little moisture, but the weight loss is mainly due to respiring CO2. We breathe out most of the food we eat, only some makes it out the other end.

marz · Aug 31, 2014

Yeah i read on another thread that curing slowly causes sugar respiration into co2..which then of course evaporates!! it’s just unbelievable that weight can disappear that way. but I guess it’s just simple chemistry….

Supercharge · Sep 1, 2014

Yes that’s correct. But it should come as no surprise to many people. A good example is dry rot. I had to pull up some floor boards last fall because I had dry rot. Dry rot is a generic name given to a process of wood rot caused by many kinds of fungus. Actually the name is a bit inaccurate, as the fungus needs moisture, but not much. The fungus releases enzymes that break down the wood, and in the process respire CO2. A piece of wood that has dry rot will be significantly lighter than normal. This weight was all lost in the form of CO2 gas. The same goes for curing weed, but it’s not a fungus that releases the CO2, but (indirectly) by endogenous enzymes that have a taste for starch.

Reuben JJ · Sep 1, 2014

Man that shit is seriously whack. It’s also pretty concerning. I just don’t want to think about the losses I’ve incurred over the years from this. Really really crazy stuff.

Kitty · Sep 2, 2014

Supercharge said:
Yes that’s correct. But it should come as no surprise to many people. A good example is dry rot. I had to pull up some floor boards last fall because I had dry rot. Dry rot is a generic name given to a process of wood rot caused by many kinds of fungus. Actually the name is a bit inaccurate, as the fungus needs moisture, but not much. The fungus releases enzymes that break down the wood, and in the process respire CO2. A piece of wood that has dry rot will be significantly lighter than normal. This weight was all lost in the form of CO2 gas. The same goes for curing weed, but it’s not a fungus that releases the CO2, but (indirectly) by endogenous enzymes that have a taste for starch.

Sorry I just want to be clear on this. You are saying that during curing, enzymes break down the plants natural sugars and the by product is co2 gas?? How much weight is lost? Does keeping nugs in glass prevent this from occurring?

Gandalfalfa · Sep 3, 2014

Coir said:
It all depends. I use rain gutters attached to the sides of a 3400sq' greenhouse to grow in and it covers the entire operating cost of the greenhouse each year in what was previously unused space. I consider that profitable.

That's a good use of space, no argument there, but you have to have a 3400sq' GH in the first place. Not too many have the room for that kind of thing..

Coir · Sep 3, 2014

Gandalfalfa said:
That's a good use of space, no argument there, but you have to have a 3400sq' GH in the first place. Not too many have the room for that kind of thing..

What? Why do you think this only works in 3400sq'? The rain gutter sections are 10' long and you can always cut them down shorter if needed to fit ANY size space.

Gandalfalfa · Sep 3, 2014

I mean to have a commercially viable lettuce crop you need a lot of heads of lettuce which would come with a larger area than a backyard GH.

Coir · Sep 3, 2014

You could always stack them!

Supercharge · Sep 7, 2014

Kitty said:
Sorry I just want to be clear on this. You are saying that during curing, enzymes break down the plants natural sugars and the by product is co2 gas?? How much weight is lost? Does keeping nugs in glass prevent this from occurring?

This isn’t new science. The phenomenon is well known to the tobacco industry. Flue curing, which has been mentioned around here before, is used partly to help solve this issue. Yes, believe it or not gas has weight. But what’s the difference of a few grams at the end of harvest? Unless you grow on a commercial scale, it makes little difference. Best not to overthink it. Anyway, off topic.

Kitty · Sep 7, 2014

OK, thanks. Never realized this before.

More on topic, I have a question about oxygen. I have two aeroponics units. If I was to feed line oxygen gas into the chamber, would this make a huge difference to growth?

Fire Bean · Sep 9, 2014

I think potentially it could. Water holds less than 1% DO. Air has 21%. If you were to make that 100%, or close to, then yes, I do think that would make a measurable difference. But……how would you prevent gas leakage? How would you automate it? Are there O2 sniffers that work the same way as infrared CO2 sniffers? How much gas would you go through per crop? Expenses - gas, gadgets, gear vs yield gain are what? Gross - overheads = profit. So you’d need to do your homework and be prepared to cop it in the nuts if it didn’t work out. Just my 2c.

Rosenberg · Sep 9, 2014

Kitty said:
OK, thanks. Never realized this before.

More on topic, I have a question about oxygen. I have two aeroponics units. If I was to feed line oxygen gas into the chamber, would this make a huge difference to growth?

Interesting thought. You’d have to try and see. It may have some unintended knock on effects. 100% o2 may interfere with sensing mechanisms. Maybe the roots won’t grow as well because they are getting all the o2 they need, but if you lose root mass you lose surface area for nute absorption.

Why do people still grow with NFT?

Why do people still grow with NFT?

Sativied

Ruler of the Whorled

Gandalfalfa

Coir

Captive

20kwDreamer

Supercharge

goliath

Supercharge

marz

Supercharge

Reuben JJ

Kitty

Gandalfalfa

Coir

Gandalfalfa

Coir

Supercharge

Kitty

Fire Bean

Rosenberg

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