High Pressure Aeroponics

Yeah, the inside of that baseball bat root system just wasn't getting much nutrient, which can cause all kinds of problems. Roots need sufficient space to breath and fluff up, like pom poms.

I went from drip (pythium) to fog (as you say heat issue, plus foggers burn up with 500+ ppms.

I went from fog to low pressure spray bars. That wasn't working too well, but during that grow I came across the TAG thread. I added EXL spray heads which helped considerably, but the more I read about TAG, I was hooked. I could smell the potential. Had to go through a huge learning curve, but now I think I am ready to rock it.
 
The main problem I had was the colas not developing - the rest of the plants were as healthy as anything I've ever grown, but the top of the plant must be connected to the center of the root mass. It made me realize that plants are like a collection of strings, bound together...

It was also crappy bag seed - I'd love to find out how the strains I'm growing now would do... especially in a 6" pipe with a 2" well head perforated pipe in the center feeding those roots... I think there's something to the NFT concept worth combining with the Aero - it's all about surface area right?

Still, those days are behind me... too much to go wrong needs too much attention to stay right... I used to enjoy that level of involvement, but now I just want a few oz's with minimal effort.

Hope to see your ladies take off... :peace: you do seem to have all the parts in place...
 
Whether we grow in soil, or aero, we have to understand root physiology. The root system is intimately connected to the plant. Each portion of root is feeding some portion of the plant. If it's nt getting enough to eat, well...

In the grow stage the tap root goes in search of water, smaller side roots in search of nutrient, as well as to anchor the plant as it grows. Once they flip to flower the female plants' entire hormonal structure changes. No longer gorging on N, she now craves P-K. In preparation, immediately below the plant a new root mass forms. When the environment is right (including room to develop in) this new root growth will look like pom poms. My 3 ft plants had volleyball size pompoms, only because there was sufficient space around them to develop. Their primary function is to feed bud development (so the bigger the pompoms the bigger, more plentiful the buds), and perhaps to flush waste out, but that could now be the job of the main roots. Not sure. Could be both.

Monitoring my flower nute runoff last grow I was amazed how much higher the pH and ppms were compared to the rez. Even in soil/mediums you must have sufficient mix to deal with this. I 'think' the minimum bucket size for a 2 ft plant is 5G and 10 would be a whole lot better. Ditto HPA roots. Cause at the end of the day, it really is all about the roots!
 
This is some interesting reading petflora! I think you'll eventually find/are finding out that this board is a little different than most. There is a wealth of WISDOM here, not just knowledge. Also a good deal of practicality, which, i believe causes people to question your (NASA's) method. I think you know your shit, just realize that this board is kind of a haven away from the egocentric attitudes that pervade other boards. Ignore the stingers and re-butt with facts till they sniff you out, and you will gain the respect you want here. just my .02 as a lurker of many sites, and participant in one. Definitely keep it up! I'm reading and learning!:Rasta::goodluck:

I do have a question: is the higher pressure what enables the smaller droplets or more complete atomization? Does the higher pressure have an effect on the surface tension of the liquid being sprayed?
 
Thanks for the kind words. I don't foresee anyone behaving badly any more. It's like any classroom. If the teacher doesn't take immediate control, they never will. I do realize where their skepticism comes from, and have no problem answering good questions to the best of my ability. If the question has already been answered. I will refer them to read the damn journal. When appropriate, I will also say "I don't know"

You asked " I do have a question: is the higher pressure what enables the smaller droplets or more complete atomization? Yes. You need pressure (100 psi is better than 50), but you also need correctly sized mist heads. Some make larger droplet sizes which are contrary to what is required/needed

Does the higher pressure have an effect on the surface tension of the liquid being sprayed? " Maybe. But the important thing is that it is such a small amount of nutrient that it is barely moist when it lands on the roots. The roots are tacky from remnants of the feeding. There simply is no better way to feed them
 
Digging for Nuggets

came across this on my search for Fuzzy info...

Less nutrient solution throughput

Plants grown using aeroponics spend 99.98% of their time in air and 0.02% in direct contact with hydro-atomized nutrient solution. The time spent without water allows the roots to capture oxygen more efficiently. Furthermore, the hydro-atomized mist also significantly contributes to the effective oxygenation of the roots. For example, NFT has a nutrient throughput of 1 L/minute compared to aeroponics’ throughput of 1.5 ml/minute.


The reduced volume of nutrient throughput results in reduced amounts of nutrients required for plant development.


Another benefit of the reduced throughput, of major significance for space-based use, is the reduction in water volume used. This reduction in water volume throughput corresponds with a reduced buffer volume, both of which significantly lighten the weight needed to maintain plant growth. In addition, the volume of effluent from the plants is also reduced with aeroponics, reducing the amount of water that needs to be treated before reuse.


NASA aeroponic lettuce seed germination- Day 12

The relatively low solution volumes used in aeroponics, coupled with the minimal amount of time that the roots are exposed to the hydro-atomized mist, minimizes root-to-root contact and spread of pathogens between plants.


More control of plant environment

Aeroponics allows more control of the environment around the root zone, as, unlike other plant growth systems, the plant roots are not constantly surrounded by some medium (as, for example, with hydroponics, where the roots are constantly immersed in water).

Aeroponics It is old info, but the part I coped/pasted her is vg.


Another Nugget

The Root System

Plant roots, which end up continually submerged in a 'deep flow' or constant drip systems will commonly be long, thin, relatively unbranched, yellowing or brown in color and seem to be lacking in fine, fluffy root hairs. The roots which develop up above the flow or pond of nutrient with a mist are typically whiter in color, more branched out and often contain masses of very fluffy, fine, bright white root hairs. FHD

This article is very interesting in that it validate s a theory about introducing more O2 in the root pod.

I'm getting closer, but the information I am looking for are much smaller (think pipe cleaner), they completely cover the fishbones, massively increasing surface area for nutrient uptake. "Aeroponics was found to be the best system compared to plants grown in liquid or sand media. Aeroponically grown plants developed a very high number of small nodules distributed all along the root system, resulting in an increase in nitrogen and chlorophyll content in plant tissues."

At LAST. They are called root hairs.
 
Yes! Root hairs are the equivalent of capillaries in our vascular system as i understand them. They are single-celled extensions of the root tip. I understand, in solid mediums, that most exchange occurs at the location of the root hair, which is why transplanting is so stressful to plants, many root hairs die no matter how delicate you are. Root hairs are also the binding site for beneficial(and malignant) soil organisms. (just my memory from Bio class, accuracy not guaranteed)

I'm trying to understand what the higher pressure does for the delivery. The questions I asked before were meant to be the same question in different forms, sorry if that was confusing. My assertion was that the excess pressure in the chamber would facilitate the smaller droplet size via an effect on surface tension.

My other thinking was along the lines that some how the excess in pressure would 'force' the nutrients across the membrane.If so, my next question would be; would a low pressure environment on the top of the plant serve the same purpose? Thanks for taking the time!
 
DrM the last article link I provided spells it all out. However, you are very close in your recollection. :thumb:

The mist that comes out under pressure is not a projectile. Keep in mind this mist is only < 2 seconds and it is expanding into a 10 -18G chamber.

The diameter of the mist head alters the liquid, so that it becomes a fine mist that fills the root chamber: any mist that does not attach to roots, gently falls to the bottom. I will try to find a video link.
 
OK I think I got it. The high pressure does nothing as far as the direct physics of absorption go, but it does allow conditions to be proper for root hair development. This development is stifled by too much liquid in low-pressure setups, too much liquid = smooth roots.....am i on point there?


I love science, and herb....convo of the day for me!
 
DrM: You are getting closer. Short feed cycles (<2 second; < 1 even better) minimize the ability of the aerosol droplets to recombine on the root/hairs. This is what TorturedSoul was asking.

The longer aerosol droplets are dispersed per feeding the more time they have to recombine into larger droplets, which defeats the purpose of HPA.

I have observed this after being told by Me2 on my other journal that 5 seconds was too long, and that I needed to get it under one second. Alas, as far as I know, you can't do that without an accumulator/pressure tank, or maybe a laboratory grade timer ($$$$). As a personal use grower, an accumulator is more involved than even 'I' am inclined to do.

Does that clear it up for you?
 
19Cam: First you need more than the pump.

Reptile Basics sells a package: fittings, tubing, timer, and an option to upgrade to the Aquatec 8800. You don't want the timer or standard pump, plus you need more mist heads, and tubing, so you will need to call them.

The lowest setting on their timer is ~ 23 seconds- not good for HPA! Google Sentinel Timer. I use the Sentinel MDT-1 as it has a built in battery back up; it also has additional inputs to control my light. It isn't that much more expensive than their DRT 1

Back to Reptile Basics: You also want additional mist heads 1, 2 and maybe 4 head depending on the volume of your root chamber (pod). Keep in mind the amount of nutrient delivered each cycle is a factor of the size of the pod as well as the size of the roots. Also get plenty of extra tubing

Example: this is where you spend your time in HPA: You need to get a feel for what head to use, an when.

A 4 head mister in a 10 G Rubbermaid pod will soak young roots-even at < 2 seconds! In early veg, you might start with a single head, but as the roots develop, change it to a dual head mister. If using an 18g+ pod, probably the 4 head, or twin 2 heads, or... The swap takes less than 1 minute :rocker: The heads are relatively cheap, and trust me, you will want them on hand.:goodluck:

Answering the above got me thinking: Since transferring my plants 2 days ago to the pod, they haven't taken off as I expected. Don't get me wrong, no shock, BUT, my plants/roots are small. It occurred to me that I was overfeeding them (amount and time). I just swapped out my 2 head mister for a single, plus I reduced the feed cycle from 3 seconds to ~1 second; the MDT 1 is not accurate at one second. If this does what I think it will, I should see a huge growth spurt. :thanks: for asking the question that made me reevaluate what I am doing!
 
Got an idea to improve my buuble back up

As you know, I lost a set of seedlings when my circuit breaker tripped over night and the young tender roots completely dried out due to lack of misting.

To compensate in my 10G root chamber (pod), I have enough nutrients to cover 2 @ 10" air stones. I know I can't do this in Flower. D2W!

I am not sure whether the O2 generated is a sufficient backup, at least being so far away from the young roots. It occurred to me that I could put a stand inside the pod and put a small bubble tub on top, bringing the bubbles within inches of the roots. Currently the bubble tub is filled with regular strength nutes. Wondering if I should just use pH balanced RO water, What do you think?

I just competed it. Time will tell whether it does anything, or is just a safety net.

FYI either way you do this unused nutes will be collecting in the bottom. Meaning your rez will be reduced, so you will need to manually put them back in the rez
 
Choosing PVC Couplers

What is so good about PVC Couplers?

They are cheap, as is the size hole cutter you need to drill through most lids. Inside each coupler is a lip/ledge that holds the starter cube in place until the plants get heavy. Long before then, you want to place a neoprene clone plug around the base, otherwise, the plant will eventually fall through. Don't wait for this to happen. Trust Me. It Will! :oops:

IMG_07346.JPG

Note the lip inside is perfect to hold starter/clone cubes

PVC Couplers also make it easy to move plants around as long as the root ball can still clear the hole in your lid. I drilled out the center of my pucks to accommodate the thick main stems that soon develops.

Clone vs Seedlings

Note that there are at least 4 slightly different versions of PVC Couplers- different heights above, different lengths below, plus different diameters below.

Not knowing any better, I wound up with these 4 different versions. Although they all look pretty much alike, choosing the wrong ones can kill/retard your grow, depending on whether you are cloning or starting from seeds.

IMG_07338.JPG

4 different PVC Couplers. The one on the left is best for seedlings. Due to its short overall height and wide diameter bottom opening, it works perfect for clones or seedlings. Any of the others will work fine for clones as long as cuttings are long enough to clear the bottom

IMG_073211.JPG

All same strain. All started same time, Is the small one a 'Runt'? Maybe not.

Problem

Notice how much smaller the upper left seedling is, although all have developed their 3rd-4th leaf set. I began to suspect something besides it being a 'runt' due to the tips of lower leaves being discolored. Top side observation (it looks healthy) would lead you to think it's just a runt, but looking underneath tells a much different story.

As you can see, the 'runt' root system has not been developing. There are plenty of short roots that were up inside the coupler (I was using the third one from the left), but they were dry, and did not extend even to the bottom of the coupler until I added the bubbler stand, and set this plant directly above it.

What was wrong? The bottom thread area of this coupler is almost TWICE as long as the other two, plus the hole where the roots are, is the smallest diameter. I swapped it out before taking these pics. The extra length in the root area, combined with a smaller opening actually prevented the atomized mist from reaching the roots hidden up inside. Figuring this out late yesterday, I transferred this plant to a short coupler before taking the pics.

Now the various PVC coupler sizes should not be a problem for clones, as long as the clones are cut long enough to clear the bottom of the coupler once roots develop. The smaller ones should work no matter what method you are using.

See pics of the topside/root group shot of all three plants so you can see where I am today. Any bets on the 'runt' catching up? The other two are growing nicely (4-6") with lots of fish bones.


IMG_07318.JPG

Note how much smaller the root system is on the left plant. I moved it into this small coupler before taking the photo today. Previously, it was in the coupler with the longest threaded bottom, and narrowest diameter opening. The roots were not getting the benefit of the atomized mist feedings.
 
Don't forget to turn your fan off, or better still put it on a timer. Even though mine is 3+ ft away and barely shakes the plants, this morning the leaves on my 2 biggest were all wilted. As I had not yet had any coffee it took me a minute to realize (and feel) the fan blowing over my shoulder. At this stage of growth I only fan for an hour or so at a time. I forgot, and left it on all night.

As a test, I put one under a plastic cup. The one I did not put under popped back up in an hour or so. So I removed the cup 3 hours ago, but it still hasn't responded
 
Rez PPMs Rising

At this early stage I only check pH and PPMs once a week, unless I change the nutes. When I replaced my nutes with DM GOLD last Tuesday, I went a bit high on PPMs (710) considering the young age of the plant roots. Keep in mind HPA doesn't require high ppms. In fact they are counter-productive.

I decided to check ppms this morning: they were up almost 160 point! That's a lot at this early stage.

I thought about why and checked my rez level. Sure enough about 2 liters had evaporated, no doubt due to very warm temps last week. And I do keep a lid on the rez, so go figure.

The one plant still hasn't recovered from the all-nighter fan episode, but it still looks healthy, just droopy.
 
Which Light to Use?

Having several LED grows for personal use under my belt, with a UFO 90 I purchased from Sunshine Systems 2 years ago for $350, I know they can work, BUT I did supplement with CFLs.

I have actively been perusing the Cannasumer threads to see what's new. Some really nice grows with LEDs, including Irishboys great results with a 180, but it costs $499, and I probably want 300 watts, which is $999.

Owning and learning about LEDs, they have some issues which are hard for me to accept, especially for the price. I am not saying LED mfgs are ripping us off: currently, they are just an expensive proposition.

Another problem is 'useful' life- forget the marketing hype. LEDs will need to be replaced sooner than you think, but that could well be 10-20 grows before significant degradation- there is simply no data to date that I am aware of to narrow 'useful' life down. What I do know is the spectrum come from different bulbs (a good thing) but all those bulbs are hard wired on the board, meaning they are impossible to replace. Personally, I am not of the mindset (or financials) to toss $500-1000 away every 3-5 years.

But at the moment, I am hot for more watts ASAP. Being perplexed whether to get more LEDs or an HID, I was excited to find a 300 LED vs 400 HID test. Alas, adding up ALL the costs, which needs to include electronic ballast, ventilation equip for the HID, both ~ 400 watt lights are relatively expensive.

Then I tripped across a journal using a Quantum T5 Bad Boy. They offer various models, but I'm looking for ~400 watts. The grow report shows excellent results, maybe not 100% comparable to a 300 watt LED, but closer than I thought possible, especially at half the price. And it has certain advantages Quantum T5 Badboy

Quantum Bad Boy 8 bulb is 400 watts equivalent

Advantages

1. 18 X 48 footprint provides better coverage for 3-4 plants.
2. You can grow in a long but narrow closet!
3. Having plants in a line is easier to work with
4. Control over spectrums
5. Bulb replacement.
6. A case of 8 bulbs, either 2900 or 6500, is <$100.
7. 8 bulb fixture is < $250

Looking at the BB grow finished here (I will post the link), the yield was damned good. Personally, I would rather spend $200 every couple years than replace an entire LED, at least until the price comes down to where I am comfortable throwing it away once the LEDs deteriorate.
 
I like the info here.... You have definetly done your reading.... I also hate the attitude though.... very cool, neat idea.... I wouldn't say it is the best way to go based off what I've seen so far... Regardless of the science behind it or it's intended results, the process just seems to painful, error prone, and "touchy feely"... And the plants growth doesn't seem up to par..... just sayin'.... Hope things shape up.... Thanks for your efforts though....
 
Thanks for commenting.

My attitude is that of any teacher. Take immediate control of the classroom, or lose it forever- and that could have happened here. Smart asses go straight to detention. One of two PMd an apology. My guess is the other is lurking. He is welcome to ask questions openly, as long as he does so in an respectful manner.

I am not saying I am a 'know it all', but the growers I have met who knew more than I, did not phrase their critiques as some here, who do not know anything about HPA. If someone knows more than I do, they are welcome to contribute in a positive manner, or they can start their own HPA journal.

PLANT GROWTH TO DATE

I began with seeds. Seedlings were ferted for 7-10 days with Botanicare Grow Big and CaMg+, but I decided to switch to the full line of Dutch Master Gold. This may have shocked them. Plus, I over fed them, even though it was only ~800 ppms. Hell that's all you need in full bloom, as HPA makes the nutes far more available than any other method. And they certainly did not like me leaving the fan on them all night. One plant still hasn't perked up, although the roots are growing nicely.

My experience with 3 prior HPA grows, is top side development takes longer with HPA, even though root development is humming along. Once the roots reach a certain level of development- BAM, the topside takes off. I am beginning to notice this now.

Also DM is revising their Nutrient Calculator, not sure what the correct weekly doses are.

In Closing

Anyway, hope you hang around for the show. Barring unforeseen issues, I believe you will see why HPA rocks, especially once we hit 2-3 weeks of bloom when the pompoms develop.

Keep in mind HPA is new to you, and so it seems more complicated than it really is. Once all the hardware is in place, the main task is checking pH and ppms of the rez, as well as monitoring the RH of the root chamber. These are the same daily chores as with any good hydro set up.

I expect to be ordering a Quantum Bay Boy T 5 (6-8 bulb) today. Most likely will use it for bloom on this grow, instead of CFLs.
 

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