High Pressure Aeroponics (HPA) Growers Guide

PetFlora

Well-Known Member
The purpose of this thread is to provide one thread for anyone interested on building a proper HPA system can find information, and ask questions.

For nubes, the following is a quick primer as to why HPA is so special:

High Pressure Aero was basically developed by NASA at least 10 years ago as it is the most efficient method to grow plants. It uses the least amount of everything, but especially water/nutrients and it requires virtually no grow medium.

Assuming proper care is given to the basics- quality and quantity of light, room temps, rez temps, high pressure system capable of delivering atomized nutrients on a deep cycle feed schedule (typically < one second feed/ one minute pause) at a minimum of 60 psi, as well as the RH inside the pod (root chamber) you will see explosive growth.

The biggest problem HPA growers must address is nutrients. Organics probably won't work as the living matter, or decayed matter will clog the mist heads. Nutrients like DM are pure liquid. In my experience, they do not clog mist heads.

Most important are the dimensions of the root chamber, distance around each plants roots. Due to atomized nutes filling the pod on such short feed cycles, the roots develop differently than they would in any other method. Instead of the plant focusing on sending the tap root in search of a water source, the frequent moisture causes lateral roots (called fish bones) to develop in order to feed off that moisture. In a dialed in system these lateral roots will also develop thousands of sites along each lateral root- they look like pipe cleaners and are called root hairs.

Mature HPA roots look like actual pony tails during veg, but once flipped to flower, a new root system develops at the base of the plant. As these roots mature, they will look like a cheer leaders pom poms. Think maximum surface area for nutes to fall upon. Each root is light, the fish bones provide air space between each roots. The size of the pom pom depends on the size of the plant: a tree can grow something like a basketball, a small plant something like a softball. You must account for this unique root development in your pod. This means fewer plants per pod, as each root system needs a good cubic foot of air space around them for the atomized nutrients to swirl and land on all surfaces.

DIY Pods. So far manufacturers have not addressed the unique pod dimensions HPA growers need, leaving them to DIY. There is no one way to build HPA pods, though one must consider the needs of plants when grown.

The ideal individual pod should look a lot like a round, but tall, garbage can whose diameter should be a minimum of 24"; height needs to be > 6" taller than the height of the plant you plan to grow. This allows for drainage and a bit of fudge factor. You do not want roots gathering on the bottom of the pod. Tables are better suited to SOG style, and/or short plants. For personal use growers a minimum of 18G Rubbermaid style tote (17" deep) can handle 2-3 short plants: several totes can be fed off one HPA system.

OK, HPA growers, fire away...
 

Bob Smith

Well-Known Member
Mature HPA roots look like actual pony tails during veg, but once flipped to flower, a new root system develops at the base of the plant. As these roots mature, they will look like a cheer leaders pom poms. Think maximum surface area for nutes to fall upon. Each root is light, the fish bones provide air space between each roots. The size of the pom pom depends on the size of the plant: a tree can grow something like a basketball, a small plant something like a softball. You must account for this unique root development in your pod. This means fewer plants per pod, as each root system needs a good cubic foot of air space around them for the atomized nutrients to swirl and land on all surfaces.

DIY Pods. So far manufacturers have not addressed the unique pod dimensions HPA growers need, leaving them to DIY. There is no one way to build HPA pods, though one must consider the needs of plants when grown.

The ideal individual pod should look a lot like a round, but tall, garbage can whose diameter should be a minimum of 24"; height needs to be > 6" taller than the height of the plant you plan to grow. This allows for drainage and a bit of fudge factor. You do not want roots gathering on the bottom of the pod. Tables are better suited to SOG style, and/or short plants. For personal use growers a minimum of 18G Rubbermaid style tote (17" deep) can handle 2-3 short plants: several totes can be fed off one HPA system.

OK, HPA growers, fire away...[/COLOR]
You should let people know that the underlined/bolded statements above are your opinion and go against most other's feelings on the matter - root hairs develop instantly, not "magically" at flower (I have no idea why you think that's so) - I had them on my clones within a couple of days of putting them in my system.

Also, the most advanced HP grower that I know of has just built a 24" tall root chamber to grow a 3 to 4# plant (5' tall-ish), so it seems as though he disagrees with your "ideal" pod theory - if given room and a sufficient support, it appears that HP roots can grow upwards/outwards to fill any space, not just down like spaghetti LP roots.

In addition, pods that big become a nightmare for getting good coverage from HP misters; if using AA, then it's a little more feasible, but still - there's a happy medium between a 5 gallon bucket and a 500 gallon container, and people need to find what works best for them.

Nothing wrong with getting some thoughts out there to start a discussion, but make sure people reading that know it's your opinion/experience and not "accepted fact".
 

PetFlora

Well-Known Member
Bob S

You misunderstood. During flower a whole new set of roots develop (in addition to the existing root system) from the base of the plant which will look like pom poms.

ROOT LENGTH Just because TF has a ton of knowledge regarding HPA does not necessarily mean he understands the importance of not allowing roots to reach the bottom of the pod, where they can slurp discharges from the plant microbes during flower. I would be shocked if he believes otherwise.

Pod Racers' TAG journal show much deeper pods.

You can have TAG without HPA, but can you have HPA without TAG? And since TAG means no accumulation /collection of roots, well...

Incorporating a screen is ok for a slight overshoot in root length (<6"), but if you are collecting 2-3ft of root mass on the screen you in effect alter the system to something more akin to DWC.

hth
 

Bob Smith

Well-Known Member
Bob S

You misunderstood. During flower a whole new set of roots develop (in addition to the existing root system) from the base of the plant which will look like pom poms.

ROOT LENGTH Just because TF has a ton of knowledge regarding HPA does not necessarily mean he understands the importance of not allowing roots to reach the bottom of the pod, where they can slurp discharges from the plant microbes during flower. I would be shocked if he believes otherwise.

Pod Racers' TAG journal show much deeper pods.

You can have TAG without HPA, but can you have HPA without TAG? And since TAG means no accumulation /collection of roots, well...

Incorporating a screen is ok for a slight overshoot in root length (<6"), but if you are collecting 2-3ft of root mass on the screen you in effect alter the system to something more akin to DWC.

hth
I didn't misunderstand; what makes you think flowering causes new "pom pom" roots to develop? You're the only person I've ever heard say that.

And no offense bro, but I'll go with TF and the makers of the Atomix system (and other commercial HP aero systems) in their thinking of pod design - why you keep on referencing DWC is beyond me, and makes me think you don't quite understand what I'm saying.

Anyhow, I'm not gonna argue anymore with you about it - we can agree to disagree.
 

PetFlora

Well-Known Member
BobS, not sure where my response from yesterday went. I seem to be experiencing problems posting here.

This pic is of a root mass somewhere in mid-late veg. In mid-bloom it was 2-3 times as thick. If I can locate that photo, I will post, as its' fullness expresses what pomp poms look like.

Note that low pressure roots look nothing like this pony tail which tons of lateral roots. The over wetness was resolved after I adjusted the mist heads away from the roots.

In my current grow I am misting for 15-30 seconds (30-40 minute pauses), so even though the first second is not > 50 psi, roughly the point of HPA, by the 2nd second it is, and after that probably pushing 100.

hth



Pom Poms.jpg
 

PetFlora

Well-Known Member
Photo update: Miss Lonely is packing on the pistils, trics and calyxes. Probably 2-3 more weeks. Her roots are brown due to adding Neptune Harvest Seaweed Plant Food (0-0-1). Also, her smallish roots are the result of me being extremely sick for 2 weeks during her early veg, and not being able to care for the plants- I lost 4, and one turned out to be a male. Most people would have given her up for dead, but HPA is capable of resurrecting the near dead, and here she is.
IMG_0768.jpgIMG_0769.jpg

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The plants below were started from seed about a month ago in a twin 12" air stone bubbler. 2 weeks ago I replaced the bubbler with my back up HPA system, but the lowest on time with this timer is 30 seconds. The explosive growth I saw amazed me, and made me rethink feed times for Lonely Lady, which I slowly upped to 15 seconds feed with 30 minute pauses- 24/7. I transferred them today into this larger pod. Note how far apart they are from one another.

The plant in the upper left and right were not getting misted correctly. The one on the upper right wilted badly about a week ago. I repositioned the mist heads and covered it in a large clear drink cup for a couple days. She has new leaves, and will be fine.

IMG_0772.jpgIMG_0771.jpg

The following root shot is from the plant in the lower left. I used it as it was easy to drape the root on the outside for the pic. The biggest plant is in the middle with bigger roots.

IMG_0773.jpg



 

PetFlora

Well-Known Member
Feed Cycle Update: The equipment True HPA growers use allows them to feed on extreme deep cycles like < one second, not sure how short their pauses are, but definitely under 40 seconds, and probably more like 10-20.

Although I use a high pressure pump, without their accumulator set up, my nutes are not under full pressure, and so each time my pump comes on it is building pressure while the nutes are being sprayed, so the initial second is not FULLY atomized. How critical is this?

Being pragmatic, for my last 3 grows I have been working to see how close I can come to their results, in spite of the fact that my nutes do not start out being fully atomized. This means there is some spittle. The question is "How detrimental is that in the scheme of things?"

The only way to truly know would be to do both systems side-by-side. I do not think any THPA grower would care to do that, and I feel the same way.

The important thing to take from this is: even if you cannot afford a $120-200 timer, you can get very good results as long as your timer has a minimum on cycle of 5 seconds. To compensate for the longer feed time, you need a longer pause and fewer mist heads to keep from drenching the roots. For the last couple days I was using a 5 second feed cycle and 12 minute pause, as the roots were taking that long to reach a tacky state (barely wet, mostly dry). The plants look healthy and are growing nicely, so this does work. And Lonely Girl is packin on the trics with 30 second feed times. It seems you can get away with longer feed times later in flower, but definitely not in veg, where the roots are focused on growing the plant instead of the buds.

But I want to dial it in more.

The key is to find the feed/pause cycle where the roots are neither too dry, nor too wet. It occurred to me that part of my problem was I was using too many heads plus long feed cycles which combined to over-moisten the roots: I was using 3 mist heads in my 15G pod. Today I reduced to one head as I am feeding ~ 1/5 the amount 18 times more often, which means the pod is almost constantly moist, but barely. I will monitor that to find not too dry, the not too wet spot. lol

hth
 

PetFlora

Well-Known Member
Wet/Dry time is a function of

1. pressure
2. nozzle flow
3. pod size
4. Mist time

As I was still missing the elusive root hair development, I made some changes over the last couple days.

I moved my plants from a ~17G tote to a 30G tote which basically reduced the residual moisture (between mists) by ~ half. This one change allowed the roots to begin developing root hairs, little fuzzies that colonize all over the lateral roots. After a mist the lateral roots look like they are lightly coated with morning dew. This is what you strive for as this means your roots are consuming nutes at max efficiency.

In tweaking this aspect, I discovered my mist heads and inline 200 mesh filter were all slightly clogged; enough to prevent the nutes from atomizing into a fine mist. Check them weekly.

Now that the mist is atomizing I can further adjust W/D times, and hopefully eliminate one mist head.


Oh, and don't forget to reopen the drain valve between the rez and the pump. I forgot, and came back 30 minutes later to 2 slightly wilted plants. No biggie, a couple rapid blasts and they are standing tall.

hth
 

PetFlora

Well-Known Member
Quick Update: Lonely Lady is not quite finished, but close. In addition to the main cola there are half dozen lower branch buds that are now golf ball size and still growing. Also, I decided to spray her in the mornings with plain RO water. Seems like this resulted in significant pistil development.

New Grow: Maybe 2 weeks ago I raised the height of the mist heads near the top (to better mist the long roots), and put the lava rock under the grate.

Yesterday, It occurred to me that the plants 'should' be better off if I raised the grate, so I put 3 large drink cups under it, thus moving the long roots very close the mist heads. I think this will do a better job of misting them and make it easier for them to deliver the nutes to the plants.

The inside of the pod is quite warm, so I upped the amount of Zone as pr DM instructions. The lava may be part of the problem; will remove it this morning.

hth
 

PetFlora

Well-Known Member
Lonely Girl Update: Cut off the light earlier today, will keep her in dark until tomorrow evening when she comes down. I am amazed how much she PHATened up under a UFO 90. Plus I was stressing knowing I had no other timer than an IGE with a minimum 30 second on cycle. Her roots did not grow much in spite of this. That said do not do this in veg, as the primary roots grew like crazy with 30 second feed cycles


IMG_0790.jpgIMG_0794.JPG


Current Grow Update:

The biggest plant (BC Mango) is rockin, close to volley ball size. I pinched it about a week ago.

The 3 Bubblegum X Lowryder Xs were stalled due to high pod humidity which killed the root hairs. I figured out how to get rid of the high pod humidity with a simple pvc vent. Since installing, RH has dropped 20+ points and the AFs are growing nicely again.

Note that I put an elbow on the vent to prevent light getting into the pod. Also my circulating fan which is out of the picture, is on the right side of the vent, which helps draw hot air out.

The other 3 are AFs, from which 9-10 seeds has not been stable. Lonely Girl is from those seeds, and has taken 5 months to grow and 6 weeks to finish.

It's already hot here, jugs of frozen water not lasting very long. 4 weeks from now puts me into mid-May; 6 weeks June, so I decided to sacrifice total yield to prevent dealing with heat related issues. I cut back light three days ago to 13/11, tomorrow 12/12 to harvest,
somewhere around mid-late May

IMG_0795 (640x427).jpg
 

PetFlora

Well-Known Member
Pulled Lonely Girl this morning; unlike bldg 7, she had to come down

Privately purchased Lowryder #2 X Bubblegum seeds., sold to me as AFs. Germed in early November. Had to force flowering due to unstable genetics.-only one of 10 seeds sexed in 3 weeks- a male that hermied.

LG was on the small side height-wise at 14&#8221;s BUT she has a PHAT bottom

Entire plant is loaded with thick gooey buds.

Yielded 100 gms wet, including 3&#8221; of main stem (~6gms)

Dry weight should come in at <half

Leaving me with ~ 2.5 ozs of primo dank

If one were to buy this this locally, it would easily run $350/ and probably $400

IMG_0797.jpgIMG_0796.jpgIMG_0799.jpg



Things I learned from this, my 4th TAG grow:

1. NUTES: Keeping low PPMS is beneficial when deep cycle feeding: Max veg 450, Max flwr 650. DM Gold nutes rock- no clogging, no pH swings

2. ROOTS: You want a timer accurate to at least one second intervals; +/- 5 seconds can allow or prevent root hair development, which are the Mother Lode of efficiency.

3. POD SIZE is critical for proper mist circulation. 30G is proving excellent for up to 4 plants

4. POD HUMIDITY about 2 weeks ago (long before normal) temperature began hitting high 80s. Inside the pod RH was high 80s- low 90s (pre heat vent). Just noticed 3/4 have balls developing, probably caused by 5 -7 days of high RH inside the pod. Anybody want to swap my BC Mango pollen for some seeds? Prefer AF type for quick harvest: Max height 30&#8221;

5. WET/DRY CYCLES I was forced to use 30 second wet cycles which created the baseball bat roots seen in the current grow root shots (see previous post), where softball shaped are much more effective when atomizing nutes.

hth
 

Atomizer

Well-Known Member
2. ROOTS: You want a timer accurate to at least one second intervals; +/- 5 seconds can allow or prevent root hair development, which are the Mother Lode of efficiency.

3. POD SIZE is critical for proper mist circulation. 30G is proving excellent for up to 4 plants
Your description allows for any number of nozzles to be used in any chamber size, a 1 second misting duration means nothing without the nozzle number and nozzle flowrate.
Mist circulation doesn`t happen with cheap hydraulic nozzles, they generate a mist pattern and generally have a good percentage of larger droplets that fall to the floor rapidly..in fact you make no mention of droplet sizes at all, which is by far the most important parameter.
The mist coverage will depend on type and placement of the nozzle(s) as well as the chamber size/shape and obstructions within it.
Staying within your design parameters.. i could use 10 nozzles with a 1 second misting duration in a 10" deep 30 gallon chamber. It fits..but it wont work.
 

PetFlora

Well-Known Member
Atomizr: Yes, of course. Perhaps wrongly I assumed that people reading this would know that I am using one high pressure low flow dual head mister: mist heads are 0.92gph; wet cycle has varied between 1-2 seconds. One head is aimed ~ 45 degrees left, the other right. Since raising the grid inside the pod, I am able to keep wet cycle at one second.

As far as mist 'coverage', using as an example horsepower off the line in a drag race; the greater the initial thrust, the faster the launch- this is the benefit of using an accumulator to fill a chamber. If I had one, the atomized mist would be more consistent and most likely a single mist head would do the job of filling my 30G pod.

One more thing Pod RH is crucial. We had a week of near record breaking heat here, at the same time that I finally had root hairs. Plant growth stopped (pod RH was pushing 90). It took me a few days to figure out that a heat vent should be the solution.. It works great, especially with the fan helping draw heat out (RH stays <62 during heat of the day).

Good News: all 4 plants are growing rapidly

Bad News: all 4 turned hermie. Will those seeds be worth germing?

hth
 

Phillip J Fry

Active Member
IMAG0786.jpgIMAG0787.jpg


My roots look like previous pics with 360 ez cloner sprayers on a ~330gph pond pump. I also use voodoo, piranha, and tarantula.
 

potpimp

Sector 5 Moderator
Man those are some beautiful roots Phillip but I think the whole thing is about how *fast* plants grow with this method.
 

PetFlora

Well-Known Member
Actually his roots are nothing special, 330gph pond pump is low pressure. You don't get formula one type growth until you master high pressure (HPA), where you deep cycle an atomized mist
 
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