High Pressure Aeroponics - Pump Design/mister layout/misters...

[muleface]

I haven't really found a lot of information on this subject. The basic premise I have gotten is as follows...

- 80-100 PSI pump
- around a 40 micron droplet from some kind of misters
- run pump from 5 seconds to 2 minutes every 4 to 15 minutes
- Pre-Pressurize Accumulator Tank
- Electrical-Solenoid hooked to an adjustable relay timer

Subjects I would like to discuss:

- what misters work best?
- size orifice on mister
- material they are made from

How many misters per Square foot, or would this be per cubic foot, or perhaps both need to be considered?

How do you size the accumulator tank? I would assume you would figure out the misters output and size accordingly, but how. 10 misters, 1/2 an hour output per mister. 5 gallons per hour total , so 10.6 ounces per minute, this would be based on PSI of the pump too.

how is the pipe laid out?

best nutrients to reduce clogging

creating redundancy for the inevitable pump failure.

actual data from grows and how they size up against other methods

This seems like a good overview site, but I would like to hear from actual pro growers that use this method.
http://aeroponicsdiy.com/

 

[muleface]

My current system is as follow.

4 - 55 gallon tubs (20 in wide, 44 in long, 18 in deep)
45 psi pump
48 - .012" orifice (0.3 mm) brass and stainless misters (12 per tub)
all being run with 1/2 inch pvc piping.
a timer that runs it 15 seconds every 4 minutes

 

[muleface]

WOW. ok....that is impressive. do you still run that kind of setup? That seems like a lot of moving parts, but that is the exact kind of answer I was looking for. At the end of the day, did you notice a real difference at harvest say compared to other setups you ran? Or did you seem more of an incremental increase? say, a couple of extra grams per plant...

How long was your cycle? Say 1 second of misting, and 5 minutes of down time?

I would love to see some pictures of you have any of that setup.

 

[CannabisNerd]

With true HP aero you want a very low misting time, around a couple seconds down to even tenths of a second. I used to use Teffen nozzles, a pretty small accumulator tank, an aquatec 8800, a solenoid for every mister, You want to lowest amount of volume between the solenoid and the mister nozzles (ex. you would not want to run a 2 foot length of 1/2 pvc between the mister and solenoid. I used to thread the nozzles directly into the solenoids, you want and instant on and off). Nutrients, as long as you stay away from organic you are good to go, I used GH micro/grow/bloom, use an inline 200 mesh filter on the intake side of the pump, I never had a clog. Misters per cubic measurement really depend on the nozzles, pressure, ect.. Only way I see you getting that part down is to hook nozzles up and trail and error, getting your feet wet with HP aero is just that, a whole lot of trial and error. I have A LOT of parts (pumps, nozzles, solenoids) that I would sell to you if you wanted...

Excellent explanation. Was easy to follow and makes perfect sense. I took a screen shot of this so I can have the info on hand when I do my build. Aren't tefen nozzles plastic? You didn't find that the brass worked better? Thanks for the info

 

[muleface]

https://www.rollitup.org/t/new-aero-setup-first-day-of-flower-comments-or-suggestions.708587/#post-9495132

You'll see pics here on the first post I beleive.

in the pictures you linked us to, what did you use as a base for your system. I am using storage containers, but im not really loving them. did you make your base?

 

[CannabisNerd]

Yes tefen are plastic, I actually did use nickle plated brass ones at first in a different HP system that ended up not being very well designed, not because of the nozzles but just the design overall wasn't very good. But the tefen nozzles are pretty good I think, they have a little screen built into them as a last resort filter and I've never had one clog, they are also pretty affordable.. They throw a good consistent mist too. I bought a couple different styles to see which one gave the best mist and went from there..

OK great. Even better they have a filter in them, I ran a couple a long time ago and couldn't remember, I think I ran brass but I know I did use the plastic ones too. The filter seems much more logical to use. Thanks again

 

[CannabisNerd]

in the pictures you linked us to, what did you use as a base for your system. I am using storage containers, but im not really loving them. did you make your base?

Have you considered 6" round pvc for your channels? The way I had my system set up was with 6" pvc with 3" net pots that held the plants. I ran the "fork" manifold along the pvc and it was along the top side of the pvc, misters screwed into the top part of the pvc between plants so roots couldn't grow into them. Is the base that your talking about the container the plants sit in?

 

[muleface]

Yeah. I'm asking about the root chamber. My current setup allows about 15 inches of roots to hang.

 

[muleface]

With true HP aero you want a very low misting time, around a couple seconds down to even tenths of a second. I used to use Teffen nozzles, a pretty small accumulator tank, an aquatec 8800, a solenoid for every mister, You want to lowest amount of volume between the solenoid and the mister nozzles (ex. you would not want to run a 2 foot length of 1/2 pvc between the mister and solenoid. I used to thread the nozzles directly into the solenoids, you want and instant on and off). Nutrients, as long as you stay away from organic you are good to go, I used GH micro/grow/bloom, use an inline 200 mesh filter on the intake side of the pump, I never had a clog. Misters per cubic measurement really depend on the nozzles, pressure, ect.. Only way I see you getting that part down is to hook nozzles up and trail and error, getting your feet wet with HP aero is just that, a whole lot of trial and error. I have A LOT of parts (pumps, nozzles, solenoids) that I would sell to you if you wanted...

so how did you power your solenoids? you had a bunch of them, were they 12v? did you use an ac/dc adapter? how did you wire them?

 

[Zekie]

Your pump pressure seems a bit low, by the time all the misters are running it's going to drop significantly.

Additionally you will be fine with 4" or 6" fence posts, I've made about 10 systems using them and they work wonderfully (many thanks to stinkbud). Round PVC is harder to work with regarding getting a good seal with your net pots, the last thing you want is leaking.

These are some good misters that have screens to filter out particulates & prevent clogging: https://hydro-gardens.com/product/monarch-misting-nozzles-m-5-6w405/

Not sure why you would want a solenoid on every mister, unless you want to throw a bunch of money down the tubes and waste a bunch of time coding them. You can get a 12V 160PSI diaphragm pump off of eBay for about $15 which will run a bunch of misters however, if you are fogging up the nutrients, the fog will allow you to run less misters because it will fill your whole root zone easily plus you will have plenty of room for expansion to other systems using the same pump.

Best of luck to you!

Peace,
Z

 

[Zekie]

you should have almost no run off, any mister inside of PVC fencepost or anything that small in size is going to form water droplets on the inside surface because the mister doesn't have enough room in front of it to disperse...

Not sure where you got your definition of aeroponics from but no one uses your definition, read R.J. Stoner's, NASA's or any academic research on the subject. The 'forming of water droplets on and inside surface' is an impossible standard that isn't used anywhere. The definition of aerponics doesn't change from low pressure to high pressure.

Peace,
Z

 

[Zekie]

Low Pressure Aero and High Pressure Aero are indeed 2 different things, while the actual definition of Aeroponics itself may remain the same, the definition of low and high are different.. Inside of a 6" tube you are going to be forming a lot of water droplets, while it is true that avoiding the formation of water droplets entirely may not be possible that does not change what your are trying to accomplish with HP Aero. Inside of a 6" tube 1/4 to 1/2 of your nutrient solution is going to be water droplets formed on the inside wall of the PVC and most of that will end up down the drain/wasted, kind of goes against the objective which is using the smallest amount of nutrients/water as possible. The point I guess I am trying to get across here is that if you are going to use 6" tube then you may as well just use low pressure aero since there would be no advantage to high pressure aero...

Here's a good high pressure system and I have zero affiliation with them whatsoever:

They cycle the timer 2 min off 30 seconds on, most people use 4 minutes on and 1 minute off (see the Stinkbud thread) which is the whole genesis for the Titan Apollo 3 ( http://www.titancontrols.net/products/timing/apollo-3.aspx ). Additionally, look at the plethora of high pressure commercial aeroponics videos on Youtube, they all use a gutter system in some way.

you may as well just use low pressure aero since there would be no advantage to high pressure aero...

The advantage of high pressure aeroponics over low pressure aeroponics it the super oxygenation of the nutrient mist when atomized. It has nothing to do with drying out the roots between pump cycles or the roots touching standing water (which they are going to anyway unless you have a 20 foot column beneath your roots).

Peace,
Z

 

[muleface]

Low Pressure Aero and High Pressure Aero are indeed 2 different things, while the actual definition of Aeroponics itself may remain the same, the definition of low and high are different.. Inside of a 6" tube you are going to be forming a lot of water droplets, while it is true that avoiding the formation of water droplets entirely may not be possible that does not change what your are trying to accomplish with HP Aero. Inside of a 6" tube 1/4 to 1/2 of your nutrient solution is going to be water droplets formed on the inside wall of the PVC and most of that will end up down the drain/wasted, kind of goes against the objective which is using the smallest amount of nutrients/water as possible. The point I guess I am trying to get across here is that if you are going to use 6" tube then you may as well just use low pressure aero since there would be no advantage to high pressure aero...

I'm going to have to agree, HP and LP are totally different animals. My purpose to starting this thread was to design the more insane version. While I can't say whether or not one works better then the other, I have no idea. I can say that the idea of HP is to use a extremely short burst of water, with a very fine mist.

http://www.agrihouse.com/secure/shop/item.aspx?itemid=24

Soil-less growing from start to finish includes: High pressure pump unit w/ high capacity accumulator, digital timer (multi-settings/ programmable), 26 ea. spray jets (.025" orifice), power strip w/ GFP, aeroponic chamber (48 in. Long x 18 in. wide x 16 inches deep) w/ 160 plants support structures, stand, 340 watt light array / nutrient recycling reservoir (7-gal) w/ auto-refill, 3-stage effluent filtration, stainless steel delivery hoses, pre-filter w/ reverse osmosis pure water supply system, drain connectors , plant growth suspension bar, reservoir over-flow protection, auto-refill, oil-filled pressure gauges, by-pass valve, additional chambers expansion ports, 85 page installation manual and growers guide, and cleaning tools.

While the above is fn crazycorn, I think that something could be made for about $14000 less and do just about the same thing.

I have issues with my system taking about 8 seconds to get to full power, then it has to drop back down. I get large droplets. It should be 50 micron drops for about 1 second. Then wait until just before the roots are dry to mist again.

 

[Eskander]

I'm looking at building a seat up of my own but I'm growing chilli peppers with a longer life cycle than most people here would want. I've been doing a lot of reading on HPA and there is a ton of misinformation out there. What is worse is that there is stunningly little real literature. What I did find on positioning is a bit contradictory at first but I'm happy to share my conclusions for what they are worth.

First things first, you need a lot of vertical space for roots. For peppers, I need about two feet. For potatoes you need about three. For MJ, you can probably get away with less but you really are better off with breathing room and the reason comes down to the nebulizers positioning. You want a mister pointed up halfway up the root chamber. A mister every square meter is actually enough even for large plants.


These are in a 1 meter tall chamber and the tops are around 8 feet tall.

Having a ton of misting heads spraying on the roots directly is exactly the wrong thing to do as it encourages lateral root growth that ultimately shields the interior of the root bundle. People talk about the <50 micron mist behaving like air which will get literally everywhere but that kind on aerosols behavior starts at about 1 micron. Big bushy roots are sexy for pictures but aren't really ideal when it comes to hydration and nutrient uptake. Think of it this way, the outside of a bush has all the leaves cause the inside gets no light. Same deal. You want roots with high overall surface area without being bushy enough to shield the core from the mist.

-Eskander

 

[muleface]

I'm looking at building a seat up of my own but I'm growing chilli peppers with a longer life cycle than most people here would want. I've been doing a lot of reading on HPA and there is a ton of misinformation out there. What is worse is that there is stunningly little real literature. What I did find on positioning is a bit contradictory at first but I'm happy to share my conclusions for what they are worth.

First things first, you need a lot of vertical space for roots. For peppers, I need about two feet. For potatoes you need about three. For MJ, you can probably get away with less but you really are better off with breathing room and the reason comes down to the nebulizers positioning. You want a mister pointed up halfway up the root chamber. A mister every square meter is actually enough even for large plants.

View attachment 3822153
These are in a 1 meter tall chamber and the tops are around 8 feet tall.

Having a ton of misting heads spraying on the roots directly is exactly the wrong thing to do as it encourages lateral root growth that ultimately shields the interior of the root bundle. People talk about the <50 micron mist behaving like air which will get literally everywhere but that kind on aerosols behavior starts at about 1 micron. Big bushy roots are sexy for pictures but aren't really ideal when it comes to hydration and nutrient uptake. Think of it this way, the outside of a bush has all the leaves cause the inside gets no light. Same deal. You want roots with high overall surface area without being bushy enough to shield the core from the mist.

-Eskander

That is fucking awesome. Is that red potatoes?

wait are you staying the root chamber is like 3 feet and then there is 8 feet of green coming out of it. so like 11 feet total? how do you hang lights for that?

 

[Eskander]

nutrient recycling reservoir (7-gal) w/ auto-refill, 3-stage effluent filtration...

As far as nutrients go, you pretty much need to commit to drain to waste. Nutrient uptake is around 1/3 in a single pass. There is hardly any reason to recycle what is left and there are a lot of reasons not to. You never have to screw with pH or nutrient tank top off and rebalancing but you also have far lower risk of spreading pathogens between plants. With hardcore filtration you can pull out the fungal stuff easily, the bacterial stuff with a lot more effort but you have zero chance of filtering out viruses. Beyond the obvious advantages there, you have things that are never really discussed on non-technical forums like this. People that have read up enough are probably aware of waste excretion by the roots. What this really amounts to gets pretty much zero attention.

Beyond analogies about drinking your own piss, let me get into some specifics. Plants excrete a pile of signaling compounds through the roots. Some of these are signaling to other parts of itself like, "I'm growing here, grow some other direction." Other things are directed at other plants and are more to the effect of, "Grow my way and I'll scoop your eyes out with a melon baller and piss in the sockets." In either case, you really don't want to constantly expose a plant to those excretions even in trivial doses.

The upside is that your nutrient consumption rate is low and you are using low concentrations anyway. Once you have spray times dialed in, your loss down the drain isn't all that high anyway. Dialing the spray time in isn't trying to achieve what most people think. There is no reason to ever let the roots dry. They don't need all that much oxygen and they don't absorb it from dry air well anyway. All the mysticism about getting as much oxygen to the roots as possible is baseless. Plants aren't designed to need tons on oxygen to the roots and many can deal with submerged roots with zero aeration as long as the temperatures are low. There is actually enough oxygen in the photosynthate flowing to the roots to cover some plants. That is how things like rice deal with the low DO in the warm stagnate water they are submerged in.

As far as tuning in the on time, keep the roots moist and try to have as little excess that ends up going right down the drain without time on the roots.

-Eskander

 

[Eskander]

That is fucking awesome. Is that red potatoes?

wait are you staying the root chamber is like 3 feet and then there is 8 feet of green coming out of it. so like 11 feet total? how do you hang lights for that?

Yes, I mean 11 feet total.



They used a fusion based lighting system...

-Eskander

 

[Eskander]

It occurred to me that many people here may not have a basis for comparison so here is what a mature plant usually looks like:



Just in case you can't count to potato

-Eskander

 

[muleface]

As far as nutrients go, you pretty much need to commit to drain to waste. Nutrient uptake is around 1/3 in a single pass. There is hardly any reason to recycle what is left and there are a lot of reasons not to. You never have to screw with pH or nutrient tank top off and rebalancing but you also have far lower risk of spreading pathogens between plants. With hardcore filtration you can pull out the fungal stuff easily, the bacterial stuff with a lot more effort but you have zero chance of filtering out viruses. Beyond the obvious advantages there, you have things that are never really discussed on non-technical forums like this. People that have read up enough are probably aware of waste excretion by the roots. What this really amounts to gets pretty much zero attention.

Beyond analogies about drinking your own piss, let me get into some specifics. Plants excrete a pile of signaling compounds through the roots. Some of these are signaling to other parts of itself like, "I'm growing here, grow some other direction." Other things are directed at other plants and are more to the effect of, "Grow my way and I'll scoop your eyes out with a melon baller and piss in the sockets." In either case, you really don't want to constantly expose a plant to those excretions even in trivial doses.

The upside is that your nutrient consumption rate is low and you are using low concentrations anyway. Once you have spray times dialed in, your loss down the drain isn't all that high anyway. Dialing the spray time in isn't trying to achieve what most people think. There is no reason to ever let the roots dry. They don't need all that much oxygen and they don't absorb it from dry air well anyway. All the mysticism about getting as much oxygen to the roots as possible is baseless. Plants aren't designed to need tons on oxygen to the roots and many can deal with submerged roots with zero aeration as long as the temperatures are low. There is actually enough oxygen in the photosynthate flowing to the roots to cover some plants. That is how things like rice deal with the low DO in the warm stagnate water they are submerged in.

As far as tuning in the on time, keep the roots moist and try to have as little excess that ends up going right down the drain without time on the roots.

-Eskander

This is an interesting idea. From a nutrient perspective its not really wasteful. I run about 7 seconds every 5 minutes. I have 48 nozzles that run at 1/2 gallon each an hour. So if i was running full time that's 24 gallons a day or 1 gallon an hour. But i'm really only running at 84 seconds of run time an hour, so that's about 34 minutes a day, that would bring my total water usage to 73 oz a day. That's only 4 gallons a week. Hell, I lose that to evaporation anyway. Also, if i need to add more liquid in my reservoir, i can just mix up another gallon at a my normal concentration, because the reservoir should be always at the right concentration. Plus, at the end of the week I throw out my nutrients anyway, i usually make a 5 gallon bucket of it and add water as needed. So really, there is no loss at all. I could toss the large trash can i am using, and use something like a 5 gallon water container with a small opening to avoid evaporation. I don't have to f with PH, The system would be a hell of a lot cleaner, I love it!

This is a great idea...Welcome to RIU.

Just a word of advice, i don't think that guy in the picture likes his picture taken. he looks like he's going to attack!

Please keep the good idea coming!!

MF

 

[Eskander]

Just a word of advice, i don't think that guy in the picture likes his picture taken. he looks like he's going to attack!

Oh, Oddjob? Yeah... we got him some meds to deal with his hat fetish and he is mostly harmless now

-Eskander