Experimenting with fogponics, could you help?


#1

Hi There,

I am trying to do an experiment to measure nutrient absorbtion and its relation to droplet size in ultrasonic fogponic systems. Fogponics has, in my opinion, more potential than aeroponics, but it has proven tricky to get right. There is a lot of noise on the internet regarding ultrasonic fogponics. Some people have made it work really good, others have had problems. Some say the problems are caused by the droplet size being too small to carry nutrients. In my opinion, the real reason seems more related to fog density and airflow.

I was thinking in making an experiment in where we weight a known amount of water and nutrients. We use an ultrasonic fogger to create the fog, and send it with a fan through a chilled tube. The collected liquid solution will be weighted and then boiled to get rid of the water. The solute will be weighted to find out the solute percentage and compare it with the pre fogged solution. I am going to use the water soluble miracle gro solution.
https://www.google.com/shopping/product/9304766303493109274?lsf=seller:8740,store:3963407762955875167&prds=oid:8670965241784436514&q=plant+food+home+depot&hl=en&ei=RUFuWeSvGMeXjwSm0IKYCg&mid=sdlF8T832|dc_mtid_8903jx325196_pcrid_107016479248_pkw__pmt__product_205563773_slid_&lsft=gclid:CjwKCAjw47bLBRBkEiwABh-PkaW8NHgWmcNdG5JxKbKrEwMkOrsiptCeTsz46lFVJeQyq-8Lsdg9YBoCPtkQAvD_BwE

Do you think it should work?


$300 Food Computer
Aeroponic System Categorization (flex/vertical/horizontal trays)
Aeroponic design guideline roundup
#2

It should be easy to ascertain if the droplets are carrying nutrients by measuring the ppm of the nutrient solution. If the nutrient isnt being atomised along with the water the solution strength will increase. Imho, if the nutrient is fully soluble and dissolved in the solution it will be in the droplets regardless of the droplet size.
Miracle gro isnt ideal as it formulated for soil growing as it uses ammoniacal nitrogen (typically a mixture of urea and ammonium. A nutrient with mostly nitrate and a small percentage of ammonium 10% or less of the total N.is better suited.


#3

How would you measure the ppm in the solution?
Do you know any brands I could use?

Thanks again Atom!


#4

@Juan1 here is a good TDS/EC meter: https://www.amazon.com/UBANTE-Professional-Temperature-0-9990ppm-Accurate-Aquariums/dp/B06XC6CV9J/ref=sr_1_3?ie=UTF8&qid=1500490544&sr=8-3&keywords=ec+meter

@Atom I too am curious which nutrient you suggest based upon your experience with aeroponics. Have you noticed that some clog, or what has brought you to your current solution?

Also, recently was pointed towards this: https://medium.com/@bifarm


#5

For ppm comparisons i use a cheap HM Digital DM1 dual tds meter, https://www.amazon.com/HM-Digital-DM-1-Monitor-Accuracy/dp/B001EHAZGW/ref=sr_1_1?ie=UTF8&qid=1500507719&sr=8-1&keywords=hm+digital+dm1
for eveything else a bluelab trunchen.

Peter, I branched out into homebrew nutrients because a) its cheaper and b) i can be sure of exactly what is in it and c) i can make up pretty much anything i might need…Downside is storing 25kg sacks and using them all before i`m pushing up the daises :wink:


#6

I had a look at the bifarm link and from a perfectionists point of view there are a few issues. The main ones being the reservoir in the root chamber and the recirculated nutrient. I would never use such a tiny accumulator, the only exception being where a long pipe run caused an unacceptable pressure drop. A small accumulator located at the remote chamber will provide enough local storage for a few cycles without pressure drop. The remote accumulator recovers pressure during the off cycle where the long pipe run isnt a problem. Pressure reducers should be located as close to the solenoids as possible and relatively large diameter tubing should be used between the accumulator and solenoids to maximise flow capacity and keep pressure loss to a minimum. Pipe runs between solenoids and nozzles should be kept to the absolute minimum length possible, zero being ideal. Id definitely avoid those 10/24 patio misting nozzles he uses ;) Heres the mist from a hypro for comparison, i`ve never had one clog yet.

IMHO, if you need to recirculate nutrients in a high pressure system you are using far too much mist. As for a bigger tank making changing nutrient a slower, less agile process…that isnt my experience.The bigger tank means you dont have a reservoir of nutes “on offer” for days/weeks. A non recirculating system without a traditional reservoir requires almost no maintenance, the nutrient remains cool, sterile and untainted with a stable elemental content from the first to the last drop. I`ve left nutrients in an accumulator for 4 weeks just to see what happens and the result was…not much.
Pristine nutes dont clog nozzles or filters and your plumbing remains clean. If the root chamber develops an issue its contained and cant affect the rest of system. Those are some of the reasons i personally use large accumulators and drain to waste.but each to his own :wink:
I just clocked the price tag, even my AA systems didnt cost that much including the silent air compressors.
Bifarm AeroKit is a high-pressure aeroponics essential kit with root temperature control, at very attractive price of $799


#7

Thanks Peter, I already bought it!


#8

So you think $799 is a good price for that system? The fog computer I have talked about in another post has a bill of materials of $750 and produces 5300ml/h of fog. I want to sell the fog computer at some point so price references are always good.


#9

I would want to see something grown in it from seedling to maturity. So far its germinated a tomato seed in some cotton wool which is a start bui you dont need mist for that :wink: My potato system cost about $225 in hardware, that includes 24L 10-bar accumulator, timer, pump, pressure reducer and solenoids/nozzles for the 2 chambers, Additional chambers will cost around $32 each.so a shade over $400 for eight providing 32 sites and 720L of root volume which isnt a lot for things like potatoes, toms or cukes.

I build my systems to use, not to sell :wink: Heres one of my pressure fed air atomising nozzles which cost $65 each (including solenoids) 6 years ago, They were a real bargain considering ive paid over $120 for a single syphon fed nozzle not including solenoid. .


note the mist plume in the pic is 10-12ft


#10

Hey Atom,
I am very interested in what you are doing. I been in constant communication with Peter. I am trying to build a HPA system using two of these tubs,
Roughneck Jumbo Storage Box - 50 gal , Size: 42.7" x 21.4" x 18"
What do you recommend that I should do? I honestly don’t know where to start.

which atomising nozzles and solenoids are you using? What type of pump system?

What do you recommend?


#11

Hi andy
I always start with the type of plants as they dictate the chmber size and planting layout. Then i consider the roots from the layout, which usually dictates the best type and number of nozzle to use and the best placement for them. The hardware to generate the pressure is the easy part, i can run a 1 gallon cloner or a 400gal chamber on any of my hpa hardware as the accumulator route provides that flexibility. .A basic pumped system (no accumulator) is limited by the flowrate and pressure .of the pump. My potato system without the accumulator would struggle to run 2 chambers :wink:
Here is one of my large outdoor hpa chambers about 6 weeks from harvest,


i`ve run this 1500L/ 400gal chamber for a full season on a tiny aquatec cdp 6800 pump that had an output of 360ml/minute, around 5.7 us gph and a 25L/ 6.3 gal accumulator just to prove it could be done.


#12

Good Morning Atom,
Thank yo so much for getting back with me so quickly. I am not that smart so I do not want to jump into anything unknown. I do not want to do anything different from yours. Can you give me a dumb down, step by step of your buildout. I would love to start ordering and setting up exactly what you are doing. Thank yo so much.


#13

@andy don’t be so hard on yourself!

@Atom HPA is extremely difficult and unapproachable to most people, and quite frankly you make it look easy. Honestly, I have been working on a HPA system for the MVP for about a month now. I’ve ordered the nozzles you suggested from Florida Sprayers. I am now just waiting on them and I should be ready to turn it on!

It would be a HUGE contribution to the community I think if you made a thread just talking about your builds. If you have a website, youtube videos, anything like that please point us to them. The more pictures/drawings/links the better.

All of that being said, I’ve re-read many of your posts quite a few times before I fully understood them. I think if you can provide whether it’s a 55 gallon trash can design, or a tote like the one @andy describes it would make HPA way more approachable and enable more people to start making it better. From my experience with hydroponics you couldn’t be more accurate in saying that it’s hard to understand until you start actually growing, but getting that first system (that is honest, and actually works) is a real barrier to most people I think!


#14

Hi Peter, it comes easy to me, but ive been at it for a number of years. When i see an aero system, the issues that will hold it back jump right out..The biggest problem is that most hpa systems are designed using a hydroponic mindset which translates into way too many nozzles and that route gives you almost no chance of producing hpa results with it. When you hear someone saying hpa is no better than hydro, its likely they used that design ;) Good to hear your nozzles are en route, Heres a soil plant during and after being converted to aero using the same nozzles. For scale, the white section of the chamber is 9" tall.


#15

What nozzles do you recommend and how many square inches does it covers?


#16

Hi Andy
it will depend on the planting layout and plant type, for example, if i switched the nozzles and placement in the systems pictured above, neither system would work… I know your tote is 42.7 x 21" .x 18" but you didnt say how many plants you plan to grow or what type which can make a difference as roots can and will affect the mist coverage. In some cases this can lead to losing some plants or having some grow a lot slower than others.


#17

Hi Atom,
I would like to grow tomatoes like the ones you grow above.

For this design.
1.Can you please tell me what you are using for this buildout? Nozzle, pump, timers etc…
2. Are you getting at least one plant per square foot?

Thank you


#18

That chamber is 5m long x 0.6m wide x 0.5m deep, its supplied by a 100L accumulator, pressure reducer and 12v dc solenoids. I charge the accumulator using a propump dp-160 (12v dc) every 2 days at the growth stage in the pic. I dont use fixed plant sites on these, they have 2 slots that run the length of the chamber for rooted tom cuttings. The plants are held in place by 2 brush type draught excluders normally used on the bottom of a door, the polypropylene bristles of the opposing strips block light and prevent mist escaping Downside of the slots is you can always find room for another cutting :wink: I dont worry about space on top of the chamber as the plants cascade over the front to the ground and climb up the wall behind…
I use long throw narrow cone nozzles in these chambers which projects the mist horizontally (in both directions) down the centerline of the chamber between the two rows of plants, The plants eventually create two walls of roots (front and back) leaving sufficient open space inbetween for the mist to pass. A shorter chamber wouldnt be as effective as its reliant on the overlapping mist patterns of multiple nozzles to generate an even coverage.
For a tote like yours, i would use a 2 row planting.layout with perhaps 8 sites (4 front and 4 back) with 3 or 4 upward firing hypro nozzles mounted 6" off the floor on the centerline. The 18" of chamber depth should be enough but may get a little tight towards the end…thats a good sign :wink: My accumulators would run a system like that for upto a week on a single charge (drain to waste). I know 4 hypro`s can keep 8 indeterninate (vine type) toms happy with 6-7 trusses on each with hopefully at least a few more months of growing to go…


#19

That is really good information Atom. Can you take some pictures for me when you have a chance. I am trying to put together BOM (build of material). Would it be possible if you can help me put together a list. Since you post the message until today I been trying find the draught excluder. I can’t find it anywhere at all hahaha.


#20

It might go by a different name depending where you are. The stuff i use is for garage doors, its identical in every way to normal width door stuff except it comes in an 2.4m length. The bristles are about an inch long.

.

Ive used these excluders as mist excluders for height adjustable nozzle manifolds where the tube sticks out both sides of the chamber through the bristles.. Necessity is the mother of invention and over time youll become an expert at seeing the hidden potential in the most unlikely things :wink: