my gravity fed air atomizing aeroponic system

good news i found a solution, glad i never throw anything away. its a three gallon paint tank with a working pressure of 60psi. its galvanized in the inside. the pipe that dips into the nutes is also galvanized, im in the process of john guesting it up. going to run it tomarow. i will calibrate my regulator by filling up my tank all the way up with water and using clear ice maker tube push the water from the tank 23.6 inches or 600mm above the water line.
sound good?
woo hoo no more dropping my 5 gallon bucket on my plants/chamber

i noticed since i changed to the #5s and your settings that the plants that were not doing well are starting to shoot out alot of roots. cant wait for it to warm up so i can really see what this things capable.

hey atomizer i was just looking at the specs for the #11 nozzle and it says
that at 1.4 bar air pressure and a head of 150mm i would get a a spray angle of 65 degrees. do you think these settings would make a 4x4 foot chamber with full coverage more possible

shit that give me 3 times my current flow rate though doesnt it

I was typing a reply when you posted but yep, its a juggling act between flowrate, droplet size, angle and throw
The mist from the #5`s looks much more like it, kind of a billowing cloud that rapidly fades down to a foggy haze. The only potential issue i see with the #5`s is they dont allow much wiggle room in the air pressure range which may become a factor as the roots start filling the chamber. If you can find some cheap #4`s, it`d be worth buying a couple as they look to be the best all round bet for a gravity fed setup.
Repurposing the paint tank saves you a few $$, it just needs a 1-3psi pressure gauge in place of the 100. A couple of coats of epoxy based paint would probably stick to the metal better than a rubber coating. A paint shop might be able to powder coat it for you at nominal cost

For now, i`d just stick with the settings your using and see how things progress as the weather warms up and you get a few more hours of sun. I noticed your coloured neoprene pucks are fairly translucent, i`d cut discs out of panda film to put over the top (white side up) to prevent any light making it to the roots.

oxanaca said:

i will calibrate my regulator by filling up my tank all the way up with water and using clear ice maker tube push the water from the tank 23.6 inches or 600mm above the water line. sound good?

Click to expand...

I`d put a mark on the clear tube so its 600mm above the center of nozzle, and set the air pressure so it pushes water upto the mark.
The bad news is, i`m almost certain the gravity feed height will decrease pro rata with the water level in the tank if you use a fixed air pressure. To make it dynamic you could use a liquid sensor in the tube connected to a relay that fires up a small low flow aquarium air pump (even a crap one can manage 2 psi). The air pump will be able to add very small increments of pressure to the tank and at a much slower rate than a compressor/regulator combo.

what would happen if i didnt treat the galvanized coating, do you think it would corrode, or maybe would it leach zinc into my solution?

do you think i could just make disks from mylared bubble wrap. im trying to avoid the hydro store as the one i like went out of buisiness and the other one still in town is extra shady.
they wont even talk about house plants they just want you to select your items, pay for it and get the fuck out!!!. i tryed talking about high pressure aero with them once and they thought
i was making it up. they were like "that not new, we have an aeroflo 60 right there"

i dont plan on touching anything, things are going to good for me to mess them up now
also i think this monday im going to pick up two of those #4 nozzles. my buddy just donated $200 dollars to the cause, so ill order em up.

Atomizer said:

I`d put a mark on the clear tube so its 600mm above the center of nozzle, and set the air pressure so it pushes water upto the mark.
The bad news is, i`m almost certain the gravity feed height will decrease pro rata with the water level in the tank if you use a fixed air pressure. To make it dynamic you could use a liquid sensor in the tube connected to a relay that fires up a small low flow aquarium air pump (even a crap one can manage 2 psi). The air pump will be able to add very small increments of pressure to the tank and at a much slower rate than a compressor/regulator combo.

Click to expand...

something more to think about, i think ill just leave things the way they are for the time being as it aint broke . its really no big deal to take my resevoir down anyway to fill it up

Plumbing supply places have more idea of hp aero than most hydro stores, AA might raise an eyebrow or two though
You dont have to use commercial panda, a disc of black poly with a disc of white on top to keep the sun off will do it. If you just use black it could heat to 60C with a bit of direct sun
The zinc wont hurt the nutes in the short term but the tank interior would ultimately rust and that could bugger your nozzles. The water level in the tube shouldnt drop all that fast so its still worth a go.

ive been thinking about the tank and i thing ill go ahead and clean the tank and go ahead and fire it up as it is, and keep an eye out for rust.
i wont need a 1-3 pressure gauge if i intend to use a water column right? seems like the water column is the pressure gauge, as my meter stick is pretty accurate.
and as i check on it once a day, i will be able to adjust my water level daily by cranking the regulator up.

also im going to start recording my water usage. it pitifully low, must be around 1.5 to 2 liters a day

i have tons of white and black 2mil plastic, ill get it done.

speaking of buggered nozzles, what kind of filter would you recommend. my nozzle has a pretty large orifice, do you think my 200 ss mesh will suffice. ill admit i havent been the most diligent in keeping my reservoir pristine, so ill bet a finer filter could help.

heres the results of 3 days

to be honest, i though for sure i would have hydro roots right now. itll be interesting to see what happens as the temps increase.

when i get my new #4s what settings would you recommend? that should be the new test

before you mentioned using air pressure to maintain sub 1 psi pressures, you suggested that a header tank with a float valve might work, is this what you had in mind

That would work. You wouldnt need the pump hooked up just charge the tank as needed. I`d use a well insulated shallow feed res and elevate it to the right height, that way the bulk of the nutes will be stored in the accumulator rather than the feed res. The accumulator can be located anywhere as there`ll be plenty of pressure available to service the float valve.

oxanaca said:

heres the results of 3 days

to be honest, i though for sure i would have hydro roots right now. itll be interesting to see what happens as the temps increase.

when i get my new #4s what settings would you recommend? that should be the new test

View attachment 2616008View attachment 2616009

Click to expand...

ye of little faith Give them a week of warm sunny weather and you`ll be wishing you`d planted something smokable or at least edible
You`ll have to play with the #4`s to see what the droplet range, coverage and throw is like. If you make the gravity feed height adjustable from 150mm-600mm, you`ll be able to choose any air pressure between 5psi and 40psi to control the droplet size and throw without greatly affecting the flowrate.

just ordered the #4s, $50 poorer.

i accidentally unplugged my cloner and forgot to plug it back in. they have recovered but im kind of threw with sprinkler cloners, they seem to suck. mine started leaking, im going to order some parts and make a quality hp cloner out of my black box

im about to start some tomato seeds again, im going to do it your way though. net pots with chunk rockwool. do you know what the ideal temp is for bottom heat temperature , ive always used 83F or 28.3c and it has given me fairily good results.

what volume do you recommend for the cooler that i will be running my airlines thru with the cold water. and how many feet of tubing do you think ill need, to have submerged?

i glued a meter stick to the oil furnace you see in the background of my aero system. i have it so that the stick reads zero mm at the nozzle. im going to try out my paint thank tomarrow. and see what happens, ive got it all john guested up.

yeah i definitely wish i could grow something smokable here. but my buddy would never allow it. good news ive got a friend that wants me to use there basement, so you never know i might be able to put this thing into action soon. its gonna be a vip only show though. luckily your invited cause your a vip

20-25C is good for toms, they`re not that fussy.
A 25L cooler with a 20ft coil of 1/2 bore hose should be enough, a lot depends on the insulation value of the tube wall, the inlet air temp and water temp. Its an easy one to test with a 5 gallon bucket of cold water and a chunk of garden hose.
As far as the math goes, a pair of #4 nozzles will pull 2.5L of air with a 1 second pulse @ 40psi. The airspeed in a 1/2" id tube at that flowrate is a shade under 65ft per second. The air will take roughly 0.3 seconds to travel through the 20ft coil. You`ll be surprised how fast air cools down.

If you use smaller tubing (1/4" id) the airspeed increases to ~260ft per second and you`ll need an 80ft coil to get the same 0.3 seconds of dwell time. Be aware you`ll incurr a pressure drop of 27psi in the 80ft coil of 1/4" tube compared to a 0.21psi drop in the 20ft coil of 1/2" tube

i have over 25 feet of 5/8 ID tubing and some one gave me a cooler that is about that volume. its not super insulated, its from the 80s all my stuffs old. but ill fix that, with some more insulation.

it got to 100F in the greenhouse today where my system was,, caught me off guard, it wont be that warm for a few days. im going to take the days before it happens again and move my system some place cooler in the building. and set up the water air cooler.

question though where do i find the math equations to find out these pressure drops and velocities, or do you store it in your head?

i knew eventually you would tell me i should upgrade my air line size.

also i think i may need to flush my roots with some ro water. should i just run ro threw for 24hr. i wish i could check the run off but their really isnt that much root mass in the chamber so i dont think i would tell me much. im going to drop my ec to 300 as well. the growth is starting to look fucked up. some of the leaves are sort of twisted. and dark green instead of purple.

I wouldnt knock stuff from the 80`s, its probably a lot better quality than the overpriced crap available today
The formulas for airspeed and pressure drop are pretty straightforward but its quicker to use an online calculator
Airspeed: http://www.engineeringtoolbox.com/ductwork-equations-d_883.html
Pressure drop: http://www.engineeringtoolbox.com/pressure-drop-compressed-air-pipes-d_852.html

oh im not knocking stuff from the 80s, hell look at my car its a mid 2000s and almost everypart of the car is failing after only 130K miles and i babyed it,
but 80s coolers did suck., at least over here.
thanks for the calculators.