Can HP Aeroponics be achieved without the use of a pump?

I learned a lesson my first year with my LP system Ionly use water soluble nutrients now and will do the same with the HP system.

Again, this is off topic, but I'll share my opinion on the matter.
I get that, but even if you're using 100% soluble nutrients you could still get some precipitation going in the reservoir... This could happen because you're not careful enough while pouring them in, eg. If you use the same graduated cylinder for the different parts of your nutes without rinsing it in between. I imagine this has to be a common mistake, it happened to me before lol...
Me, I like to brew my own nutes and I have access to fine grade chemicals. We should all be brewing our own nutes, the price of 1L of stock solution is about 1/5th of the commercial ones. There are plenty of good open source nutrient recipes for MJ or you could copy the ratios of your favorite commercial one and find the chemicals for it (You don't have to use the exact same reagents as they do, you can often get really close with 1/3 of their ingredients)... My recommendation is to use HydroBuddy. it really makes it so much simpler than doing the math on your own, plus if you use the listed chemicals on its database it even tells you which ones are compatible with each other and divides your stock solution in 2 parts accordingly.
Do your nutes have bioenhancers included? Well add them separately whenever you feel like you need them... Me, I run everything with my hombrewed nutes and I add trichoderma, mycorrizhae and some bacillus species. These symbiotics feed on the exhudates of the roots, which produce more exhudates if you feed them Fulvic Acid and Humic Acid. That's it, that's all I use... Regretfully for you guys, I'm not in the US, so the places and the brands I buy my things from won't be of any help to you... However, I've used PHC bioenhancers before, an american brand I believe, and they worked just as well. But they were expensive to me as they were imported.
That being said, impurities might and will cause clogging, so good filters are mandatory. You can choose weather to filter your stock solution or to put filters on your system or, to be entirely safe, to do both...

PD. If you have any questions regarding this subject PM me and I'll help you however I can.

Bob, I have been contemplating buying bulk chemicals needed to make my own nutrient formula over the past 3 - 4 years. As you said it would save a lot of money. I will have to wait another 2 years before I dive into that as I bought bulk nutrients at a discounted price 2 years ago and i estimate it running out around the end of 2018. Still I wouldn't mind trying it out on a smaller scale on 1 of my systems.

I agree even soluble nutrients could clog a HP sprayer. Even now with my LP system I usually pour each individual nutrient in it's own gallon bottle first, make sure it dissolves then pour 1 at a time through a filter into the reservoir. My first year growing I didn't use filters and the sprayers got clogged. Luckily I caught it on time and was able to clean the sprayers and bought a bulk load of filters. I plan on putting filters on the HP system when I build it.

My nutrients have no bioenhancers in it. I did do something a little different with 3 of my grows but haven't done it since. Twice during the grow when I drained the reservoir instead of adding the normal amount of nutrients I added compost tea instead for that week. At the end of the week I drained it out added new water then it's regular dose of nutrients. I did see a slight difference with the plants but not much as I would see when growing out of soil. I don't think I could get away with doing that on a HP system. I know I'm probably missing out on some new things but so far I've had no complaints.

Pothead,
Well yes, like everything else in this art, brewing your own nutes comes with a learning curve, so trying it out on a smaller scale first would be the wise choice.
Me, I have never used a compost tea, it frightens me a little not knowing what could be living inside it I guess, lol... As I said before, I've never used bio enhancers on HPA either, but I suppose one could get away with it spraying them manually over the roots once a week. Trichoderma is really for protecting your grow, because they block many pathogens out. Mycorrizhae on the other hand keep another number of pathogens out, plus they expand the root surface area, therefore allowing your plants to absorb more nutrients. They're truly something to explore indeed, both of them combined provide a wonderful shield and enhance your growth making it grow faster and healthier. The bacillus I use are preventive and keep another number of pathogens out, plus they are compatible with both aforementioned symbiotics.
As I mentioned before, the only trouble I'd see is feeding these colonies. They will feed just fine on root exhudates without anything added, but if you really want to keep the colonies the healthiest the best way is to provide humic acid and fulvic acid. Maybe you could pour these in the reservoir along with the nutes but I've never tried it and I remain skeptical about their "clogging effects"... It would be nice to see the effects of HPA on a root system well colonized by mycorrizhae.

I wouldnt run any organics in hpa, you could with AA as the nozzle orifice is 10x larger. I run home brew nutes along with ro water. The bulk chems i use are all Yara brand which are good quality and fully soluble. No problems with the plumbing, accumulator or nozzles even without filtering. If i used the hard water that comes out my tap it would be a different story

So I guess it's confirmed then, thanks Atomizer. I'm thinking of a separate misting system, like LP just for the organics... lol... maybe feeding them once a week
Or sticking to misting them manually for the time being

I would never try compost tea or even organic nutrients in a HP system. I used organics once when I tried pouring in the reservoir using a filter it looked like dark brown sand on the filter. I can only imagine the horror of finding all the sprayers clogged on a HP system. I used the rest of the organics I had on the plants growing out of soil.

Bob, I don't have the ability to PM you not sure if it's the browser, the Mac or I haven't been on here in a very looooooooong time.

Hi everyone, I'm going to offer some new information to this thread.
First, I have a few years of experience using low and high-pressure aeroponics.
And my favorite is HPA. My nozzles have never clogged up even though it recirculates the waste.
Why, you might ask? The key is keeping the nutrient clean and refreshed. My system runs at 80 to 115 psi.
From what I read hear, it seems most systems run a large pressure tank with a large reservoir.
I found it's best to use a 1.5 gallon pressure tank with a small 3--gallon reservoir. I do this for two reasons. One, I allow the system to run almost dry, down to just 1.5 gallons left or less.
So when I add 1-gallon of fresh nutrient, at least 60% is new.
Second, bi-weekly or monthly, I can purge the system completely and add 2.5 gallons without much waste or difficulty.

You will find it much easier and cheaper to control 2.5 gallons of nutrient than 5 or more.
By the way, I'm giving a free course on how to build your own aeroponics system which will include my schematics, parts list, and assembly diagram with videos of me building it. Signup for the free video here: http://aeroponicsdiy.com

lol, sounds like a shameless plug
I dont recirculate nutes in hpa or AA because its better not to and theres no reason to. If you have a big accumulator you dont need a res, the accumulator IS the res Running drain to waste provides 100% balanced nutes with a known elemental makeup with every misting until the tank is empty. In my book, mixing 60% of fresh nutes with 40% of old nutes doesnt equate to fresh, clean nutes, you`ll have 60% new (known makeup) + 40% old (unknown makeup) = 100% unknown
With DTW you dont have to control any nutes, or check / adjust ph or ec. You simply fill the accumulator with nutes which have 100% known makeup, unplug the pump and leave the system to do its thing until its time to fill the accumulator again.

Me, this is what I would do in future grows, and it's neither of both... I'd run HPA, because I don't really see the point of AA, with a small reservoir and pump it into the system once the accumulation tank loses pressure... the capacity of the tank is completely dependant on the number of nozzles, but I'd go for something that needs refilling once a day... pump is gonna work either way, it might be for a longer time once a week, or for shorter times 7 times per week... talking about the lifespan of the device it doesn't really makes much of a difference. The reservoir would be filled accordingly, so that at least 3/4ths of it are gone by the end of the week. Why Atomizer? Well these are my arguments:
-I can look into my reservoir, but I can't look inside my pressurized tank :/
If anything was to Form because of a contaminant I could have a straight look at it in the res...
-I can react quicker to nutrient changes that need to be made without having to dump a big amount of nutrients away (this could also be done if you empty the tank and catch whatever is inside it, adjust it and pump it back in, but it seems like a lot of effort).
-Even though the tank is pressurized and sealed off light, aeration of the solution is still an issue... if you have a big accumulator tank, well that means there's a lot of water lacking oxygen where bacteria and other pathogens could thrive in. If somehow a pathogen managed to get in your "perfectly sterile" environment well... you can see where I'm going.

Applefarm, like I said in earlier posts, I don't really see the point of recirculating HPA anymore... how much water per nozzle would you say comes back to your reservoir? If they get shut by solenoids, it's really just the amount stuck right in the nozzle (which could also be avoided/minimized using antidrips)... how much of the mist condenses back and flows to the drainage of your root chamber? It shouldn't be much if you're spraying 4 seconds every 5 minutes... so in my opinion, it's worth avoiding the risk of having something unwanted (that could develope within the root chamber) flowing back in and contaminating the rest of your reservoir...
However, I will take a look at your tutorials, it's always great to try and lay down your knowledge for someone else to learn or criticize.

I see where your coming from Bob but you cant compare an accumulator to a res which is open to the air even if you put a lid on it. Airstones or a recirc pump for surface agitation to keep things fresh just increases the potential for invasion. My accumulator is sealed and under pressure, it doesnt behave like a normal hydro res. The nutes come out of the tank the same as they went in, I dont use airstones,pumps or sodium hypochlorite in my stock solution containers to keep them aerated and pathogen free
Once you have a system dialled in you dont need to alter the nutes. When it comes to dialling in, i can pump an hour or a few days worth of nutes into the accumulator. It makes no difference as the pressure reducer will provide the same pressure to the nozzles whether the tank has 40L of nutes in it or just 2L. Not many hydro systems can run on 2L of nutes as it wouldnt be enough to cover the pump.
With a small accumulator/res combo you would be tied into a full tank dump situation because the pumps cut-in, cut-out points will be dictated by the pressure switch

AA has less components than hpa, compressor, nozzle, solenoid and timer. Its easier to put together and the mist quality and coverage is better, The downside is cost

Atomizer. I get it, it's not the same environment within a pressurized tank, but anaerobic bacteria can still prosper in such an environment as they are not very affected by such pressures. I'm not saying it can't be done, but being sterile is often an issue... I don't add sodium hypochlorite either (nor any other chlorite), I keep it well oxygened and add hydrogen peroxide within the shock values once a week... I usually dump my reservoir once every two weeks, but this could be done once a week with a smaller reservoir.
In my opinion, it's a matter of "taste". Personally I'd feel more comfortable knowing that I can always look inside my Nutrient Solution and add whatever I please to it. But hey, I respect the fact that you have your methods well writen and they clearly work the best for you... I don't believe there's a big difference in costs (if both were HPA of course).
I'm merely pointing out the fact that there are plenty of ways of doing it right.
As for AA, you said it right, the difference is the cost. And it's not that small, the nozzles are expensivier and the silent air compressor as well. How much of an improvement can you see in your grow when using such a system? I don't see why mist quality is better, if you provide enough pressure, water droplets should be the same size using AA or HPA and they are both saturated with oxygen. How do you measure the mist quality? lol
One benefit I can see of AA is that you mentioned the possibility of using organic supplements , that could tip the scale on that direction, but I haven't really found any documentation of succesful grows while doing it! Have you done it before? Do you believe in organics at all Atomizer?

The cost difference is about the same as buying a retail system versus making most of it yourself. Some things you cant make like the nozzles and solenoids, a silent compressor with an output equivalent to a bambi 150/500 can be built for $115 which saves $1500. Nozzle $130, solenoid $22 and timer $14. If you shop around and make what you can its not expensive.
If you ever get the chance to compare AA mist with 30-40psi air pressure and hydraulic mist at 150psi, the difference will be pretty obvious. One AA will produce the same amount of mist as 20 hydraulic nozzles, the difference is you can control droplet size and how much liquid is in the mist, AA nozzles also respond much faster and dont suffer with run on issues.
You should use whatever method your most comfortable with, i find HPA and AA easier and much less work than lpa, nft, dwc and even coco. As for whether its worth it, if you stick 20-30 nozzles in a 10gal tote and mist for 30 seconds then the answer is no. it wont be any different to lpa,nft,dwc etc. Most people tend to run hpa similar to how they`d run a lpa system, try this analogy; you buy an F1 car and cant manage to get 5 yards down the road.. therefore expensive F1 car cant be as good as your old beat up jalopy, Tools/workman comes to mind.
I`m not against organics, i just prefer to run synthetics because they are the better fit.

I would prefer a large accumulator tank. I don't have to deal with a reservoir. I can mix up a fresh batch of nutrient water, fill the accumulator tank once every 4 - 7 days depending on how many sprayers I'm using. That alone would give me more time to work on new projects. Now my only problem is trying to find a large accumulator tank with a high psi max rating at a reasonable cost in the States.

Try finding it in Mexico :S

The selection of accumulators in the US seems about as wide as decent hp pumps and cycle timers are over here..ie not very lol. A 26.42 gal vertical 150psi tank with a replaceable bladder costs $256 here, mine was a bargain at $76. If you keep your eyes peeled you can sometimes get lucky.

I've been searching and will continue to do so.