I’ve had the buckets of Jacks and Cal-Nit on the shelf for some time… Guess it was time to dust them off and use them. Thanks for posting the notes!
@anon32470837 Thanks for making the switch as well. Without you doing so, I wouldn’t have been tempted to do the same 
Love every single one of your threads. You spark such great discussions and I always have a good read!
So far I am still very very pleased with how the Jacks is doing in my rez. However, it isnt quite as amazing as I was originally thinking.
Yesterday morning I decided to lower the EC back down towards my normal levels. Some of the leaves are really dark green and more of them are looking darker than I think is good. The odd section of burning spots on some of the leaves is spreading, so I decided to see if a lower EC would help. I dropped it from EC 2.0 to 1.8, then down to 1.6.
At 1.8 there was a hint of PH drift UP, but not very much. It was within the error range on my meter. However, at 1.6 I am seeing a very slow but steady climb in PH. It looks very much like what I see with just plain tap when aerated if I allow the temps to climb - which I have been.
It finally dawned on my that I had been running at relatively hi concentrations - which was enough to keep the PH rock solid. At lower concentrations, there isnt enough buffer capacity to lock the PH in 100% against my waters tendency to raise the PH to the mid 6’s when aerated and warmed up.
On the plus side - It is still out performing the Advanced Nutes PH Perfect even with my added MES buffer - but not by as much as before.
Plus - Im still seeing zero cloudiness, and zero smell even though Im using less than 1/4 of the pool shock that I was previously. Actually, more like 1/8th as much shock. My fuzzies will like the lower chlorine levels.
Thanks! Thats a very nice compliment. Glad my fumbling around is worth while 
I’m noticing my water has an ungodly ability to raise PH as well. I’m on city water though, so it’s gotta be something at the treatment stage. It takes a lot of PH down to lower my PH even after almost 2.0EC worth of jacks. Within a couple days it sticks around 6.5. Going to get my RO unit back out soon and test it that way, I may be better off if I do that.
I am not using any shock in mine however, I can’t find calcium hypochlorite locally it’s all that “4 in 1” or 7 in 1 junk. Still no smell or cloudiness though, a major improvement on that end.
I need to get a replacement probe for my hannah meter though so it may be that. The plants don’t seem to be complaining too much yet lol.
Day 70
Things are still looking good most places, but the burned spots are spreading some and the dark green is also spreading as I mentioned above. It will take a few days to see if the lower EC makes a difference. Still too few amber trichs on the most advanced buds, and the majority of buds still have a good ways to go, so Im not really that close to harvest even though Im maybe a week “over due” compared to others growing this same strain. I guess killing off roots isnt the “best practice” for growing fast autos
The roots are struggling to get the fuzzies back. Its going much slower this time. I have been playing with ON/OFF timing since I moved the nozzles to the top of the chamber, but its slow progress. Maybe due to the plant slowing down near the end of life? Or more likely the poor things are wore out from repeated attempts to kill them off?
Anyway, the roots dont look really bad, just not really good. Some areas of really good looking fuzzies but mostly smooth, slightly off white. No smell and no slime, so thats good. Well, they do smell, but its like fresh hey or new mown grass almost. A good smell.
The plants are really starting to smell more. From outside the house, near where I suck in fresh air (I thought) the smell is very noticeable.
Im starting to think my yield will be half decent, but no way to tell for sure until its dried, but the screen is fairly full. I cant wait to see what kind of grams/day I end up with.
If it ends up taking 90 days total to harvest, I would need a minimum of 630 gms dry to match the 7+ gms/day of my last harvest. Thats not gonna happen, but I am thinking I will possibly beat my soil grows 4-5 gms per day - maybe.
PSA announcement - dont ask me about gms/watt. Its a meaning less, useless number, and is just “stoner science” as far as Im concerned. Gms/watt may possibly have a very small usefulness in comparing two light fixtures, but I doubt that as well. In any case, dont take this personally, but I am on a campaign to eliminate gm/watt use in pot growing! 
@Mohamed - I still need to go back to your first long post and respond to several things there, plus I havent finished answering your later posts - sorry. However - I want to ask a couple more questions to the ones I asked above. I will put them all here in one place to make it easier.
How big do the roots get with the plants you intend to grow?
Also, how long is the grow cycle from the time they will be in the system to harvest?
You said something like a 45 meter long grow bed - why that particular nummber?
Will this be one long chamber or how do you see configuring the space?
How wide, tall etc?
How many plants total and how much space does each plant need up top?
In other words - more details please if you can share them. It will help as far as giving advice.
It could be several things, but if your water has chlorine/chloramines in it, then bacterial growth is probably not the cause. More likely is carbonates/dissolved carbon dioxide in the water.
At least a part of that need for lots of PH down is the built in buffers in the Jacks itself.
The way buffers work, there isnt a single or specific PH that you get. Buffers RESIST PH change UP or DOWN. They do not in and of themselves have a specific PH that they cause.
The nutes in the jacks will tend to lower the PH down from what ever your waters starting point is, but the ending PH will depend on where you water starts, and how much UP pressure there is from the carbonate/C02 cycle.
The buffers in the Jacks will tend to help keep the PH at what ever point it ends up after mixing. More buffer capacity - from stronger concentrations of Jacks - means it will be harder to force the PH UP or DOWN. Lower concentrations of Jacks will be easier to force the PH to change - in either direction.
Buffers dont lock PH down to one number - they just slow down and resist any thing thats trying to shift it around from where ever it happens to be.
Using RO did me no good and may even have made the water more susceptible to PH swings (lowered the buffer capacity). It will be interesting to see if you get different results.
Is that a top drip in coco or? I assume thats the rez in the white container they are sitting on? They look happy to me 
Thanks for the info, I’ll keep you posted with my results.
My system is an exact copy of @Mr.Sparkle’s, as I needed to downsize and keep things stealthy without too much compromising 
I’ll finish answering these questions before I go back to the earlier post.
As far as shoot sizes - I have no clue of Im getting bigger ones than normal or not. Mainly because these are all new strains to me that Im growing for the first time for me, so I have nothing to compare them to. As you say though, yields have been excellent.
Im using grams/day as opposed to the more often seen grams/watt that most folks in the pot growing community have been using to judge and compare total yield at the end of a grow. In my opinion, grams/watt is useless for much of anything. You can skew grams/watt just by vegging longer. Without a time component, its useless, Even adding a time component doesnt really fix it.
One person can grow for 150 days (5 months) at 300 watts and get 600 grams dry yield. Thats 2 gms/watt which isnt bad. Another person can grow for 4 months with 200 watts and “only” get 500 grams/watt. But at the end, person one got 4 gm/watt (which is excellent by that standard)
while the other person got 2.5 gm/watt - which is not bad by that standard. However, person #2 yielded a higher gm per day 4.1 gm/day vrs 4 gm/day. So person two had 1/2 the gm/watt but got more gm/day. Person two will out yield person one with a LOWER gm/watt number.
In my grows, the difference is much larger.
Grams per day on the other hand is simple and tells you something useful. How many grams did you harvest - on average - over the total time of your grow? Light information has no bearing on that. If it takes 100 days to go from seed to harvest, and you net 100 grams dry yield, than you have 1 gram/day yield. If you net 500 grams in 100 days, then you have 5 grams per day dry yield. I dont give a crap what lights you used or how bright they were. I just care how many grams I ended up with over the entire course of the grow. Thats the only number that counts.
In soil, I averaged a little over 4 gms/day. My other hydro grows wee more like 6-7 gms/day with the HPA grow at the hi end of that scale at just over 7 gms/day.
If you just look at gm/watt, my HPA numbers were insanely hi at well over 4 gm/watt - BUT - thats because I left the plant in veg a loooong time and the total time from seed to harvest was like 5 months. That skews the gm/watt number way up, but doesnt effect the gm/day the same way.
Gm/watt is stoner science
I may be misunderstanding your thoughts here, but I think you may have under estimated the amount of water you will need with drain to waste in aero - HPA or AA.
Early on, I throw away maybe 95% or more of the water coming out of the nozzles because the roots are just too small to drink much. Almost all of it drains to the bottom and gets dumped. Even late in the grow, I toss out maybe 1/4 to 1/2 what comes out of the nozzles.
I never have bothered to actually measure the runoff and I probably should, but I dont really care. My total nute/water consumption at max is close to what it was with routine rez changes in normal re-circulating hydro.
The larger the root mass, or the more it fills the chamber, the greater the water use efficiency is, but there is still a lot of waste compared to what the plant actually consumes for growing when its just sitting in water.
According Atomizer (I dont like him, but he does seem to be very good at these kind of details), you are better served basing your nute/water consumption on the size of the root chamber. In other words, you need to know how big the chamber is first. THEN, you calculate the amount of water you need to “fill the chamber” with the correct size droplets. The plants will drink what ever they need and the rest it tossed. Early on, the efficiency will suck, but it gets better as the roots grow.
So - that means root chamber sizing is very very important to figure out up front. Its really where you have to start.
To do that you need to know how big the roots will be by the end of the grow. You dont want to choke the chamber or over fill it with roots, but an over size chamber will waste more nutes. Its a balancing act that may take some trial and error tests to determine the ideal chamber size for your particular plants. Plus you then need to figure out how many nozzles, at what flow rates, spray angles, and coverage.
These nozzles I. using are close to that 400/1 air/water ratio too, but they will work on lower air pressures than any of the others I Looked at. Actually, they may be a bit better as the liquid they are based on is fuel oil and not water. I am thinking that the lower viscosity of the water will make for slightly higher liquid flow rates for the same air use. In my tests, there wasnt that much difference though. Maybe 10%. Siphon heights/head pressure makes a far larger difference in liquid flow rates.
Yeah, most air compressors rate CFM at 40 or 90 PSI. You have to guess what it would be at lower pressures. I agree too that they are mostly pretty optimistic in ratings.
In your situation, I dont know if you need a quiet compressor? They have much lower capacity per dollar of cost than a normal contractor (noisy) air compressor. I cant imagine you having a 45 meter long grow in your bedroom, so maybe if noise isnt a factor you could get by with a more powerful, cheaper, but noisier compressor?
I dont really know about that - but - keep in mind that neither system will be running the pumps full time.
Hmmmmm - I may be wrong on that as far as the 1000 PSI HPA. Do they use an accumulator tank? I would think not. A tank sitting around at 1000 PSI would be dangerous - and it would require expensive pressure reducers or regulators or hi pressure tanks. I have no clue really what they use.
Normally, in our small grows, its ideal to use an an accumulator tank that hold the nutes under pressure. That means the pump only runs intermittently when the accumulator runs down the pressure to the point it needs to be re-filled.
Same with an AA system. You need an air tank that supplies the nozzles through solenoids that are controlled by timers. The air compressor only runs intermittently. In my stet up, the compressor runs for aprox 2 minutes every 90 minutes or so.
In my HPA setup is was a similar ratio, but I forget the exact numbers. They will vary a lot depending on the tank size and the pump capacity/flow rate AND the cut-in and cut-out points of the pressure switch you are using to control the pumps/compressors.
IIRC, Atomizer was using huge tanks and his (large) compressors ran for a few minutes every day or so.
Oh yeah. Thats a factor for sure
Are you thinking 1 liter per minute for the entire grow system? That seems low to me, but thats just a wild gut reaction.
Still, your going to need a LOT of solar panels to supply the pumps, and lights - especially lights. Are you going to have batteries as back up to run the system at night/cloudy days etc?
So much information… nice update once again
Thank you sir!
Anyone remember that old Bill Cosby joke about the windshield wiper? Well, thats how I have been feeling about forgetting to turn the timers back on - over and over and over again.
So - I just finished installing my very own “DUMB-GUY DUMB-GUY DUMB-GUY” alarm system.
The wiring was simple - just connect 12v to the center post on the switch and run a lead from each of the other two posts to the + power input for the two timers. When one goes OFF, the other one turns ON.
The second timer didnt have the configure option I thought it did to start in the OFF mode, but this will work. When the switch flips, the timers sends a 0.1 second pulse to the alarm, them waits 30 seconds and repeats - until I turn the switch back the other way.
Its loud enough that I can hear it any where in the main part of the house, but not so loud that my wife - or the cats - freaks out. The LED flashing isnt all that bright but cant be ignored if you’re in the room.
I figure the only way I can screw this up now is if I turn off the power strip the timers are hooked up to. I could power the second timer from a different location, but that would require a second 12v power supply. I have some on hand, but they are all being used. Its highly unlikely that I would turn off that power strip and forget to turn it back on as it also powers the three Inkbird controllers and the pump for the rez.
Actually, I already have an alarm for that power strip - I have a night light plugged into it that will come on when the strip goes OFF, so I think Ive covered all the bases… hehehehehe said the fool to the idiot…
Totally with you on the g/w being bunk in all situations. If you’re growing outdoors or for personal use, grams per day is by far the most useful measurement. And if you know you smoke a half eighth a day it’s apples to apples.
I like to include g/Kwh tho, because it tells me how much it cost to produce x amount of bud, inclusive of all equipment including AC and whatnot. Then I can directly compare that to the cost of buying it instead of growing it. Person two in your example would not only produce more per day, their price per gram would be substantially lower.
That’s a lot good info Larry, thank you!
That’s as if you read my mind! That’s exactly why I was asking about the hang time because I also have this chart and I was thinking I could roughly figure out my average droplet size by measuring the hang time but I didn’t know how I would go about doing that. That’s why your laser method is so cool, it’s easy and it will enable me to get an estimate from withing that tank.
Okay I get it now, I’m with you on that. Whenever I saw g/Watt I would immediately search for how many days it took till harvest and what was the ON light time for vegging. I think your method is more accurate only because experienced pot grows should have optimized the plant lighting to begin with anyway, meaning that they all should have provided enough or more lighting than the plant would actually be able to utilize. In other words, they are all dancing around roughly the same DLI (Daily Light Integral) number recommended for pot either by using Metal Halide or LED. So with lighting not the limiting factor (and I would also assume nutrients and temp are kinda optimized) then the limiting factor for yield will become the growing time as you mentioned.
Thinking about it, yeah g/Watt seems like stoner science as you said because it’s kinda meanless. I think it was originally intended to be geared more towards lighting efficiency and electricity consumption assuming that the grow cycle is your average 3 months. I would think because people who originally used those metrics were mid to large scale growers that they cared more about electricity consumption than smallish growers. Nevertheless, a much more useful number for their case should have been g/Watt-hour or more realistically g/kWh because it would be more telling of how many grams they get related to their total electricity consumption as it doesn’t care about how many days they grew their plants so it’s kind of a pure energy to mass conversion factor and the major influence here would be the efficiency of the type of light they are using (everything else optimized like nutes and temp). If they want to be even more accurate, then they should include the energy consumption of the whole system in the g/kWh figure like fans, pumps, heating and of course lighting. But because artificial lighting is the major consumer and it doesn’t depend on geographical location or the seasons (like colder or hotter areas/seasons), it can slide somewhat.
It’s good to hear that your drain to waste water consumption at max was roughly the same as recirculating. There’s some contradicting info about this subject but most are saying that it a little more. As you said, drain to waste water consumption when the roots are still small might be a contributing factor. But because I intend to do large scale this will be minimized because like other large scale growing, the seedlings will sit densely packed at first then moved to another growing container less dense then again moved to the final container. So you see, it’s not like the same plant will stat and finish in one container which might make the issue of drain to waste a little better. More on that upcoming. But these drain to waste estimates you mentioned were for your earlier Hydraulic HPA grows, correct me if I’m wrong! But maybe you current AAA can attain even better figures than those.
You’re right on the that. The 1000 PSI HPA system these guys are using doesn’t need an accumulator tank. This Danfoss pump they are using is rated for continuous duty and the nozzles have an internal pressure switch that doesn’t open till I think 300 PSI if my memory serves me correctly. Yes an 1000 PSI accumulator would turn into an explosive device 
Also I don’t like the idea of a water/nutes accumulator tank for HPA, it adds another complication and it’s harder to clean if at all. An air tank however is fine and I don’t care about the noise.
Sadly the whole idea of an accumulator tank whether for water or for air is only viable when the water pump or the air compressor (the actual air pump itself) flow rate is much bigger than what is needed in the grow. Meaning that if a water pump is rated for 1 Liter/minue flow rate and your grow is using say 50 milliliter/minute then you can run the pump only 1/20 of the time. Same thing for air. That puts me in a situation where I either use a hugely oversized pump (considering this larger grow, it will be truly huge!) or I use a continuous duty pump. It turned out there’s a kind of simple solution to that, using a slightly over-rated Triplex Pump (these are the very popular pumps used for car washers and misting systems) I can achieve continuous duty if I use it at a lower rating (of course coupled with a continuous duty motor which I already have, not the brushed type motor that one usually see mounted on this pump) it should be fine. Just for the sake of info on this particular topic, here’s a web page explaining this stuff:
Here’s the chart provided as how using the pump at different RPMs and PSIs affect pump life. The pump in the chart is originally rated for 10,000 hours:
1 liter per minute continuous at the end of life for the plants, meaning in the last few days before harvest the water consumption will be something like 1 liter/minute x 60 minutes x 24 hours = 1440 Liters, that’s huge for one day but again I believe I wasn’t totally clear. I’m hoping it wouldn’t be like that as I will do trials on part of the system first before embarking on the full system.
As for lighting, fortunately I’m using natural lighting so the energy consumption is much much less otherwise. For now I’m thinking a about 3 kW solar system should cover the needs for the day and enough batteries for night and cloudy days. With artificial lighting this figure would have been around 15 kW or more!
It’s no secret anyway, I want to grow primarily leafy greens, their roots don’t usually grow more than 30-40 cm long and the roots don’t consume much space horizontally, more like a circle of 15 cm diameter. The grow cycle is from 30 to 45 days from seedlings. The system I’m thinking about is kinda modular so I can start experimenting with only one module to determine its parameters. It’s kinda crazy, I don’t know if it will work or not but I would like to experiment anyway, so here goes:
That’s me standing in the photo btw, looking pale . So this thing is actually a water tank (you know the round standing type) so the ends are covered but I removed the covers in the photos. It is rotating around its axis very slowly, like once every two minutes or so (this is configurable). The plant roots in the photo are their expected actual size but of course they won’t be pointing towards the center like what is depicted in the photo. The tank is slightly tilted at 3 to 5 degrees so the accumulated water can run to one side where it will get collected. That’s all technically not that difficult to achieve as I have experience in motors and motion control. The tricky part is, how will the roots behave in this kind of balanced gravity. I’m calling it balanced gravity because I don’t know of any other term. It’s not zero gravity like NASA stuff but because the tank is in continuous rotation, the net effect of gravity on the roots is zero during its life time. I searched long and hard on the internet for any papers investigating the effect of said “balanced gravity” on plants without success.
Two things give me hope, the first what you said about roots drawn to water and the second is that shoots are drawn to light. There will be a small water pipe running along the center axis of the tank and that’s where the nozzles will be installed. So the nozzles will be in the center shooting outwards. From the looks of it, the water droplets forming on the root will not go down because it’s continuously rotating so the droplet will soak into the roots when the plant is upside down a minute later (every half tank rotation because it’s rotating once every two minutes). Droplets falling down due to gravity will be collected by the roots under. I have absolutely no freaking idea but that’s why I’m trying it.
The photo depicts the tank used for the final grow. For seedling, it’s the same exact tank but with much much denser holes and they will be transplanted once they get to a proper size. So the plant will not start and end in the same place. Once stage transplanting is good, maybe also two stage transplanting but this will be more labor intensive of course.
I should have 45 modules of those that’s why I said the grow is 45 meters long. It will be done in a green house although I wished my bedroom would have been 45 meters long so any thought on that would be good I guess!
What a fascinating idea!
I dont have time to go into any detail, but I Love the creativity in that idea and how off the wall it is. I dont think its going to work very well, but I still love it!
Fast points - the roots and shoots are going to be ‘exercised’ a lot as the tubes rotate. Have you looked into what that may do to the growth?
If you do manage to get fuzzy hairs, they act like velcro. As your roots flop from one side to the other in the tube, they will stick together rather than staying spread out - I think.
Gotta run… love that idea!
I briefly looked for this and it seems to work. There are other setups that exercise the roots in this manner: rotary aeroponics - Hledat Googlem
My growing is also only for short plants, I wanted to optimize for that, even for the greenhouse itself. So these plants can hold themselves well unlike taller plants.
I didn’t think about that. I thought roots touching each other from other plants when flopping would be the problem. These can eliminate any benefits from the setup. Well what if I somehow can place a plastic net inside the tank and fix it a few inches from the openings so somehow so roots can grow on them at some point, would that help?
Very interesting stuff @Mohamed. Most of those rotating setups had the lights in the center and rotated the roots along the outside so they could all be dipped into a single tank as the tub turned. You are reversing that and substituting aero for hydro.
Very cool idea!
Ok, I take back my reservations. On the roots sticking together - a mesh or trellis type of thing might work just fine. It would need to be fairly open so it didnt limit mist penetration, but that might work just dandy.
I suspect you will need to do some trial and error grows to see what works - or even if anything is needed. if your roots are short enough and strong enough, you may be fine with nothing.
Sounds like you are pretty set on going the hydro nozzle rout with the 1000 PSI pumps? If so, I will quit pushing the AA setups
In that case, given a 1 meter diameter drum, with the nozzles in the center, here is what I would suggest.
I would try to find some nozzles with a throw distance of 0.5 meters or so with maybe a 45 deg spray angle. Solid or hollow cone probably wont matter, but flow rates will - more on that later.
I would also only have nozzles on the top side so they shoot UP only. With the nozzles only shooting UP, the mist will just reach the roots at the top that fall within the cone angle. The mist will shoot up and hit the hanging roots on top. However, the majority of the mist - including the larger droplets, will fall to the bottom of the chamber and hit those roots. Some of that mist will also be hitting the roots on the sides as the drum turns. In other words, each pulse of mist will get several chances to hit the roots. This should increase your efficiency as far as waste water going to the drain.
I think you are going to want relatively low flow rates and short throws in each tub to make this work best. Hi flow rates and long throws will over wet the roots rather than supplying a good, consistent mist environment. Remember that you dont really want a wet/dry cycle if possible.
How do you control the ON/OFF cycles with the 1000 PSI systems? Regular solenoids dont sound like they would work. Do they just turn the pumps ON/OFF? Im not wild about that idea as it would make for sloppy timing and mist cycles with varying droplet sizes as the pressure built up and dropped back down. Even with 300 PSI ADV valves, you will get pretty sloppy cycles as fara s pressure gradients at the nozzles.
Here are a few quotes from the guy I Love to hate - Atomizer - as far as chamber size vrs mist timing, flow rates, etc. These are not in any particular order.
There`s no wet/dry time with AA, the roots are suspended in constant mist. Finding the right mist density is the first hurdle, too much, too moist or too large a droplet size and everything is soaked. Too little or too small a droplet size gives too dry a mist the roots cant use. Pause length is set to let the mist gradually fade down to a light haze just before the next pulse. Use too long a cycle and the mist is completely gone (too dry), too short a cycle and excess droplets start building up on the roots (too wet).
The target daily throughputs are based on full coverage of 5-80 mist which hangs for the entire pause duration and then some so the roots are never without mist. If you dont have it, the best approach is to make the pulse as short as practical to maximise the number of mistings and adjust the pause based on root wetness and structure. In a lot of cases you`ll find the target daily throughput numbers are reasonably close even though the pulse and pause timing will be different. If the ideal total nozzle flowrate for a chamber is 4.5LPH, and you need 3 x 4.5LPH to get the coverage, you are forced to use 3x the pause to achieve the same daily flowrate.
In an ideal system, you would set the misting duration based on flowrate and chamber volume. For early growth, the misting duration would provide 0.02ml -0.04ml per gallon of chamber volume. For later growth, 0.06ml per gallon.
The interval between mistings is adjusted to provide the target daily throughput, which will be somewhat dependant on environment variables (light,heat etc). As an example, a 26 gallon chamber with one 1gph nozzle would need a 0.5- 1 second misting duration in early growth and upto 1.5 seconds for later growth. The interval between mistings for early growth would be 35-70 seconds (dependant on the misting duration setting) with a target daily throughput of 1.3 litres. For later growth, the interval would be around 50 seconds with a target daily throughput of 2.65L. The name of the game is to inject mist little and often to maintain an optimal aeroponic environment.
Most aeroponic systems have flowrate, coverage and/or control limitations which provides a defined wet/dry cycle rather than a constant mist environment.
There are 2 types of aeroponics, high pressure and air atomised. These are the only ones that can fulfil the droplet range requirement and provide the necessary level of control…Having said thet, they can also produce hydroponic results if too much mist is used. An aeroponic system should be designed to deliver the absolute minimum amount of mist with tight control, You can easily increase the amount of mist but its impossible to reduce it below the design minimum if you have too much
Ideally, the misting system should deliver no more than 1ml of liquid per 100L of root chamber volume, The mist should consist of 5-80 micron droplets and be directed into open space to prevent localised root wetting and uneven mist coverage. Very few folks would contemplate building a system to those specifications so its no surprise that data is a lttle thin on the ground
That should get you started with some calcs on flow rates, through put, etc.
Im wishing I could do something similar to this with pot, but dont think its practical for that size plant. If you can get the flow rate low enough for the nozzles, you could potentially set up a continuous spray that delivered “just right” mist levels constantly - something I have been wanting to do but have not found a way.
I forgot to follow up on this. I think hollow cone will serve you best because they will have a lower flow rate. I suspect that will be a factor if you are running 1000 PSI setup. Fisrt, you need to figure out the volume of each cyclinder, then the flow rates based on Atomizers numbers above should get you in the ball park. Then it will be a matter of try it and see what timing/flow rates your plants want.
Day 72
No big changes. The roots are still slooooowly recovering fuzzies, but I think part of that is Im forced to over spray to make up for not having enough nozzles.
Ive also decided that the solenoids Im using are not good enough for the water side control. The QC just sucks. Plus, they lie about the specs. They make two different “versions” of these solenoids. One is 0.02MPA - 0.8MPA pressure range. These dont open until they see 0.02MPA of positive pressure. They work fine for the air side because Im running over 5 PSI. 0.02MPA = 2.9 PSI.
However, on the water side, the head pressure I have isnt close to 3 PSI, so I get no flow even when these are “open”. I bought several of the 0.0-0.8MPA versions, but after taking several of them apart - they are exactly the same solenoid - just different labels. There may be a slight difference in the internal springs, but its not uniform. I think maybe they install springs randomly as well as labels.
By messing with the internal springs, I got two to work more or less, but they are not consistent or uniform in flow rate, so one of my nozzles puts out a lot more mist than the other one.
GRRRRRRR
So, after looking back at the Delavan info, I decided to try using them as per the mfg spec - as a true siphon nozzle. I have been using them with a small but positive pressure feeding the water into the nozzle - which is why I needed the solenoids to stop the flow when they were OFF.
If I switch to siphon mode, then I dont need any solenoids on the water side. I should also be able to lower the air pressure - and thus the air consumption rate. Ive been having to run at 6 to 8 PSI to get good droplet sizing and hang times. By adjusting the siphon height, I can go down to as low as 3-5 PSI and still should get good atomization - I think.
So, I need to build a small tank with a built in “float valve” of some sort that I can adjust in height relative to the nozzles. I have several ideas and will test them out over the next few days.
Im probably going to leave things as is until harvest though. I just dont have enough room to get into the chamber to work.
That’s exactly it yes, it is because I’m using sun light.
The only issue with a mesh is that the roots will cling on to it and might be harder to clean between grows. So it would be great if I don’t have to use it.
I’m set on hydraulic because I tried to look for continuous duty air compressors, they are big and very expensive. So it’s a matter of power consumption and price for me. Washer pumps at 1200 PSI and 2 L/m are cheaper and are cheaply serviceable so I might get two pump heads from the get go and replace it in case one fails.
Oh I was thinking more like a 360 with 3 nozzles rotated 120 degrees apart but I guess you have a point there, shooting mist down is pointless as I will be pushing them towards gravity.
I know my average flow rate based on this calculation:
4000 plants, each plant will consume a max of 7.5 Liters in its 40 days life cycle.
Total water for 40 days = 4000 x 7.5 = 30,000 Liters.
Average consumption per day = 30,000 / 40 = 750 Liters/day
Doubling the number to get the worst case condition of daily consumption (just before harvest) = 750 x 2 = 1500 Liters/day
Total nozzles flow rate= 1500 / 24 / 60 = 1.05 Liter/minute (That’ the basis for sizing the pump)
I have 32 drums total.
So flow rate In minutes per drum= 1.05 / 32 = 32.8 ml-max/drum/minute
Drum size is 1000 Liters = 278 gallons
flow rate In minutes per gallon = 32.8 / 278 = 0.12 ml-max/gallon/minute
That’s roughly double the number Atomizer said (0.06ml per gallon) assuming his mist cycle was 50 seconds. I looked at several sources and it seems the my plants’ water consumption is pretty consistent. These calculations were for hydro so maybe I’m comparing apple to oranges and Aeroponic systems actually have lower water consumption so I might end up using half of the amount of water:
I think it can be good for something like an SOG grow, assuming of course it works. In the photo I posted, the drum was 80 cm diameter but since then, I moved to a 100 cm diameter to give more room.
Okay, here is the other part of the idea:
I think you already guessed it. Unlike what is shown in the photo, I’m going to use one of these 3-nozzle modules to cover a horizontal run of 24 meters. The whole system will be two runs. so I will have 6 nozzles in total.
This is why I’m researching continuous-duty pumps because it might end up running semi continuously.
With this setup I can control the speed of the module so it’s basically controlling the flow per drum. I can speed it up in areas of new growth and slow it down in areas of old plants. I also can start the pump when the module is situated in a place along the run that’s not underneath roots, once the pump builds pressure, I can then start to traverse the system with a set speed to dispense water. It should also make coverage more symmetrical as roots are being covered from all angles.The traverse speed can be max 1 m/s so the 24 meters run can be covered in 24 seconds. 0.5 m/s speed will dispense double the amount of water in about 1 minute.
The reliability falls onto the mechanical system which can be made reliable enough.
After what you said about the nozzles, I think I will end up using two nozzles both slightly tilted from vertical shooting up with opposite angles.
Will the moving module hit roots? Because 1.0 m/s is pretty fast. I don’t really have an answer to that but I moved to a bigger drum (1 meter diameter, 1000 Liter instead of 500 Liter) to try to avoid this issue. I can also try to cover the space above the module so the roots above would slide on it and protecting them from the speeding module. I’m trying just to minimize the cost of the system dramatically by using some of these techniques.
@Mohamed - Dang Im rushed again, but here are a few points.
You are good at throwing curve balls at me! Im talking about the three nozzle modules on the moving track. Very cool idea - but - I dont think its going to work well as far as creating a good mist environment.
I think we are both still misunderstanding each other on some of these details - at least I am.
Are the drums open at the ends or between sections or sealed in some way? Im asking because you need to contain the mist inside the drums while also allowing for fresh air to enter the root zone. They must also be light tight. Even small openings where air can enter will result in air pruning. The “fresh air” needs to be at the same temp and humidity as the inside of the drums or beter yet, it needs to enter slooooowly through some sort of light tight mechanism.
In my case, I use fabric pot material - heavy felt type material that allows air flow but is sort of almost light a little bit light proof - but not really enough. This material “breaths” easily, and blocks maybe 80-90% of the light. The chamber is surrounded by a foam box that adds the rest of the light blocking while not being sealed very well at the edges so air can freely enter/exit. I also have a small heater between the fabric and foam to keep the chamber warm. You do NOT want cold or hot roots. They do best right around 70F. Much over and root rot settles in. Much colder and growth slows way down.
Your sliding track misters will do great for “spraying” roots, but I dont think it will work well for creating a good mist environment.
Atomizers numbers for filling the chamber are based on a single mist “pulse”. They are NOT litters/minute or hours. They are per ON cycle.
In other words, the goal is to fill the chamber with mist. Dont think about spraying the roots and dont worry about the roots at all at this point. How much they drink has no bearing on these calculations. ALL you are trying to do is “fill the chamber” with droplets.
To do that, you need to add .04 to .06 ML/gallon of chamber volume/ON cycle.
In your case, with a 278 gallon drum, lets say you are shooting for .05ml/gallon. That means when your nozzles turns ON they need to put out 278x.05ml = 13.9ml = and then they STOP.
That single pulse of water - 13.9ml of nutes - when broken up into 50 micron droplets - will “fill the chamber” with the correct level of mist.
Now you have to turn the nozzle OFF and wait until the mist starts to fade - wait for the ‘hang time’. Only then do you do another mist pulse of the same 13.9ml.
The total number of nozzles, and flow rate of the nozzles you are using, determines the length of the ON time. If you are using only a few low flow rate nozzles, you may need a long ON time to deliver that 13.9ml. If you are using lots of nozzles or they have hi flow rates, you may not be able to get the ON time short enough to keep from over spraying and creating too much mist or too wet roots.
For example, my ON times are less than one second while my off times are closer to 60 seconds. The nozzles stay OFF far more than they stay ON.
Notice that NONE of those calculations had anything to do with how much the plants drink. It doesnt matter how much or little they drink. If you create the perfect mist environment, they will have what they need at all times.
Arrhhhggg - lots more to say, but gotta run
EDIT: I forgot the most important question I had. It sounds like your thinking of the 1000PSI system running constantly? With no defined ON/OFF cycle? If so, thats a whole different animal from HPA. Not that it wouldnt work, bu its a very different set of design goals/restrictions.
There are many things I have to figure out still.
Yes, that’s what I was trying to say. Let me explain, so one span of 24 meters will have 16 of these drums. The track running through the center of the drums carries a 3-nozzle module (or maybe two nozzles now) which can move from the beginning of the 24 meters till the end.
A misting cycle should look something like this:
1- check if the nozzle module is at the beginning of the track (no roots are above the nozzles at this location)
2- start the pump and wait some fraction of a second till pressure buildup is complete and the nozzles start spraying as desired.
3- Now start moving the nozzle module along the run of the system (all while the pump is still running).
4- When the nozzle module reaches the end of the run stop pump.
5- retract nozzle module to the beginning of the system again to start another cycle.
Now, how much water I dispense in each drum is controlled by the speed of the nozzle module rather than an on/off cycle simplifying the system.
The drums are open at both ends except for the openings of the drum at the beginning and end of the system here is a concept two-drum unit:
This is what I imagine it to be at the moment. I need to optimize even further for cost although.
If the system span is only two drums like in the one in the photos, the openings of the drums at the beginning and at the end of the system would be covered and only allow the two red wires to pass though pass though.
If the actual drum resembles the one in the photos, there will be a little space where mist can escape and that’s between the drums. I think I can manage isolating that area and also shading it using low cost materials, like a white-side/black-side plastic film.
As for fresh air entering the drums, I would have never thought of that! Well I might be able to think a way to introduce air to the drums. I totally skipped on that. A small suction fan at the opening of the last drum might be able to move air very slowly through the entire span of the system if I can manage a well enough “seal” around opposing drum openings. I also might be able to run an air hose with small openings inside the drums along the run of the system. Or I might end up doing without it because there will be a constant air change in the green house and from my experience with air, it finds its way through. I think the best idea though is to plan it as to provide a reliable source of air to the roots from the get go.
I’m a little lost as to why you use the fabric material inside a foam box, if the foam box will stop air from entering anyway. If I’m understanding correctly, could you have just used a light proof container with an air hose pumping air into it (from a small air pump) like a standard DWC container except there’s no water inside. Please explain this further.
So can I say that roots in Aeroponics are more sensitive because unlike soil or hydroponics because there’s no dirt or water mass to protect them from fast temperature changes. As dirt and water act as heat capacitor that resist sudden changes in temperatures. Much like how humans get sick if they are exposed to sudden temperature changes, it seems that roots do too. But still slow changes in temperatures doesn’t affect the roots that much as long as these temperatures are in the correct bounds, like I witnessed in hydroponics. Because water is constantly being misted in the root chamber, the root chamber temperature should always be a few degrees lower than the ambient temperature around the drum. So this translates to: if I’m able to control the green house ambient temperature well enough then the root chamber follows suit and doesn’t need controlling dedicated to it, and that’s what I intend to do for now and, in theory at least, it should work. I might instead do is regulate the nutrient water temperature by cooling it when needed to 25C or even less if possible. This way I might also be able to control the temperature at the root zone. Any ideas?
So I chose water tanks as the drum because the ones I checked have three layers (white-black-white) so there is some good heat rejection and isolation there (not much isolation perse but it might work).
Yes I understand that these calculations has nothing to do with how much plant drink, they are different ways to estimate the average water consumption and see if the two arrive at close figures.
According to observations on how much plants drink and transpire in their life time, the rough calculation I made about max water consumption is 32.8 ml-max/drum/minute (drum is 1000 Liters = 278 Gallons)
According to Atomizer, my figure is double his recommendation: 278 gallon x 0.06ml-max/gallon = 16.7ml/drum.
If the total ON+OFF cycle is 60 seconds which is kinda is, then Atomizer recommendation becomes 16.7ml/drum/minute.
I’m actually happy that these two rough calculations arrived at close figures (32.8 vs 16.7 ml/drum/minute). I grossly overestimated in my calculations to arrive at worst case conditions. Anyway, more later.
