new low pressure aeroponic system

[growman1001]

Not trying to sell anything just want to see how much interest there may be. I've done some grows in a DWC bubbler type system(DIY 5gal buckets) and as the plants got big it was soo hard to properly manage(check PH/EC, change water, etc). So from my own frustrations I developed a system, it still uses the 5gal buckets for the plant roots to grow in but a unique bi-directional valve allows the nutrient delivery and return drain to use the same pipe automatically. In-between pump cycles all the liquid flows back to the reservoir, this is not like a circulating DWC system where some liquid remains in each bucket.
If your using a grow tent like in my case the reservoir can be outside of the tent so you can do everything without even opening the tent. The bi-directional valve is contained within a bulkhead which is inserted in the bottom of each bucket(multiple buckets can be daisy chained together). Just need to drill a 1" hole, add the valve(threads together), attach the 4 nozzle spray ring inside the bucket(all push fittings), connect the single 1/2" pipe back to the submersible pump in the reservoir and its good to go. It couldn't be more quick and simple, a 4 plant system could be up and running in minutes...
You would just need to supply buckets(cheap at Canadian tire/home depot) and net pot lids or whatever you want to use.

I can provide some pictures if this is hard to visualize, I do know there are some aero systems available, but they are elaborate and expensive. For anyone wanting to get into hydro/aero or larger scale growing it doesn't get easier then this.

Sorry can't share any pricing yet but it would be reasonable. If this sounds like something you may be interested in or have any questions let me know...

(also good for growing large vegetable plants

 

[Larry3215]

Not interested in buying anything, but I am curious about the details.

Not trying to be critical, just want to see if Im picturing this correctly:

1) you turn on the pump (on a timer I assume), and it runs water through some number of LPA sprayers inside the bucket?
2) Because there is only one pipe connected to each bucket, there is no drain available while the pump is on, so the bucket starts to fill with water.
3) When the timer turns OFF, the "two way valve" allows the accumulated water to drain back into the rez, through the pump, as soon as it turns off?

Two more questions.

Why do you need a two way valve? Water will automatically drain back through any aquarium pump. This is how virtually all flood/drain systems work.
But, the rez needs to be lower than the buckets for gravity to drain the buckets.

Or are you using another pump to drain the buckets?

It seems like Im missing something or Im not visualizing this correctly.

Again, nit trying to be critical, just trying to figure this out. Im seriously into aero, so always curious about new approaches.

 

[growman1001]

I'm open to any questions and comments good or bad, so thanks for showing interest and taking the time.

All of your statements within your questions are correct, the purpose of the valve is to act as both a drain(gravity), and supply to the spray nozzles.
Its essentially a diverter valve, if no water pressure is present it opens drain holes around its base so water can return back(leaves about 1/8inch of water). When the pump turns on(by timer) the pressure closes the drain holes and diverts the water up to the spray nozzles. I have been using a 20 second on time and 5 minutes off with good results, but this depends on pump size, bucket qty, pipe lengths, etc.
I'm a big supporter of DIY and kept things very simple with off the shelf parts, the valve has 1/4 NPT ports, so standard fittings can be used. it would be easy to build custom sprayer arrangements, and It could be used in other configurations as well like ebb and flow or maybe cloning systems.

Here's a couple pics

 

[WrigleysHaze]

For me, this system is too complicated and, in my opinion, has a high error rate.

Why? You have to raise the bucket and you lose space, plus you could knock it over and in the worst case it breaks. If there is a power cut, the ladies are gone in 2-8h, depending on whether it is day or night.
The drainage can be blocked by roots or something else. The pump can run dry or run water all over the place depending on the reservoir.

A plus point is that it is aeroponic and needs very little water and nutrients.

And finally, of course I have to say that for such a small project and a lot of DIY it's great. But for larger systems you would have to build it differently, I think.

 

[growman1001]

Thanks for the feedback, I have all your same concerns, aeroponics does have its risks but also rewards. The configuration pictured is the most basic/cheapest, for a more failsafe setup I would use square buckets, and side mount the valves. This removes the space loss, and you can have water always remain for safety(you set min depth based on mount height).
The valve itself is very tolerant to large particles, blockage concern was at the top of the list during the design. It has 6 redundant passageways for both drain and feed, so a full blockage risk is very low. Testing is still ongoing in multiple configurations and I can report no blockage problems so far.

Certainly the more components involved increase the risk of failure, but for an aeroponic system this is about as simple as it gets.

This system does work on a large scale, pipe/pump size is adjusted, and multiple pumps can be run from a single reservoir and multiple reservoirs can be used to maintain levels, that's what I heard anyway

 

[WrigleysHaze]

That makes the system better. For me it is still too much work compared to the DWC system and I have not heard of the difference in yields or the like. In hydroponics, many systems can be combined well with each other.
With every run you will find new ideas and improvements and upgrade.

 

[Larry3215]

Roots blocking drains is a problem that exists for every hydro system that recirculates, and many DTW systems as well, so I dont see that as a down side. Its also no more complicated than those same recirculating systems, and simpler than some RDWC setups.

I personally would be tempted to use a separate drain line with a much larger diameter pipe. That will be more root tollerant than a smaller pipe - even with multiple outlets. Plus no fancy drain valve with moving parts. Roots always know where the drain is and go for it. Of course the trade off there is more cost for pipe, fittings etc, plus it makes the system more fixed in place - you will have a much harder time moving buckets around.

I have been using a 20 second on time and 5 minutes off with good results, but this depends on pump size, bucket qty, pipe lengths, etc.

I personally think cycle timing should be adjusted to suit the roots and nothing else. I want to commend you on your short ON time. The vast majority of LPA growers seem to want to use long ON times - which is a waste. All you need to do is wet the roots. Anything beyond that is a waste,a nd will actually reduce the efficiency of the oxygenation cycle.

The whole reason to do LPA or any type of aero is its increased oxygenation. Thats the only reason it works better than DWC or other types of hydro that keep the roots submerged or flooded in water.

The key thing to know is that oxygen gets absorbed into water very slooooooly. The top most very very very thin layer of any water exposed to air will reach 100% DO very quickly - BUT - it takes a looooong time for that oxygen to penetrate to deeper layers of the water. Thats why we aerate water. The act of aeration is all about exposing more water surface area to the air as fast as possible. Its NOT about bubbles. Its all about exposing the most water surface to the air as fast as possible, and then replacing it with new water that has not been exposed.

With LPA, if you leave the water running more than the bare minimum needed to wet the roots, then you are actually depriving the roots of O2. The idea is to just barely wet the roots, then let most of that water run off. That will leave a very thin layer of water covering the roots. Remember that very thin layers reach 100% DO very quickly.

So, if you can keep a very thin layer of water on the roots, thats the ideal situation. It only takes a second or so to actually wet the roots. More than the bare minimum ON time is counter productive. Your 20 seconds is probably too long, but its much better than most folks do.

As far as OFF time, you want that to be as long as possible, but you do NOT want the roots to dry out. Its better to be conservative here and do another ON cycle a little too soon rather than a little too late. I tend to think your 5 minutes is probably pushing things, but that will depend on how much the plants are drinking, humidity levels, temps etc.

Over all I think you have a nice system setup. My only real concern is roots in the drain, but thats a constant for many systems as I said above.

 

[growman1001]

Great bunch of info, I've spent some time testing on-off durations, mainly just viewing root moisture levels. But I have experiments planned to test various cycle times head to head on plant growth over time. I'm sure every plant type has a goldilocks zone for peak growth. But how big is this range and really how much difference does it really make, that's what I really want to know.

Back to this root blockage thing, I know I'm a little bias but I think you would be surprised how tolerant this system is. There are a few reasons for this, first bidirectional water flow reduces the chances, flow in only one direction will block much quicker then a flow that alternates in direction. The second more important factor is any large root pieces just don't enter the system. Its much different then a recirculating DWC system, roots are not constantly being tugged on by deep flowing water. If a larger root strand was to actually break away from the plant it will simply lay in the bottom of the bucket. There isn't enough water flow to carry it into the valve, the drain back process is fairly slow and there isn't enough depth or flow to move a large root piece. The small particles that can flow within the water just can't possibly cause a full blockage, even if a partial blockage did happen the valve self flushes and it would clear, this is an inherent function.
I can say this with confidence, I have a system running here right beside me that has massive root structures, each 5 gallon bucket is entirely filled with roots. If I lift a plant out of the bucket the root structure still looks like the 5 gallon bucket and I've disturbed these plants much more then normal as I'm always testing various things, I know I've broken many roots. I don't filter the water in any way, honestly I expected at least some plugged nozzles but nope. This is what the water looks like at the moment(over a week old), I have never seen any large roots in the reservoir(months of testing) or even small pieces. If anything I think both the grow buckets and reservoir act more like sediment collectors.

 

[Larry3215]

I am surprised your not having root blocking issues, but that is very good news. Sounds like you are getting it dialed in pretty well. Good luck with it!

 

[hash slinging slasher]

Hi, new member here. I'm attempting a similar setup to yours but instead of 5 gallon bucket I'll be using a large rubbermaid container. Any update on the grow? How're you liking the setup?