HPA Adequate nute/water delivery? Design for clone thru harvest

My first clones dried to a crisp. Hopefully this thread can turn into a how to if yall have good input.

Here is what the size of the clones/root at start:


I feel like my chamber had good mist amount, but since the clones roots are so small, perhaps not enough surface area for them anyways.

Below was my nozzle set up and a misting demo, my system is all 1/4" flex tube, aquatec 6800>shutoff switch(95PSI-70PSI)>2 gallon accumulator tank> solenoid> Nozzles(trying to fix this part with this thread)
Was doing 2 sec/5 min intervals


This is what I've found:

Atomizer said:

Put the 4 nozzles on a single line and feed the line from both ends using a tee on the pump. The modded layout gives you an even pressure across the nozzles and minimises loss from excessive tee fittings (original top layout) or excessive tube lengths (bottom pic layout). View attachment 1692297

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Atomizer said:

Loss increases with flow rate, it`d be best to use 1/2" tube throughout if you can.
1gpm flow through 3ft of 1/4" tube will cost you 1.54psi. (42" head). The same 1gpm through 3ft of 1/2" tube will cost you 0.05psi. (1.35" head)
You`d need a pump capable of at least a 7ft head to drive 2 nozzles with 1/4" tubing. The same pump with 1/2" tubing could handle 62 nozzles

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Fatman7574 said:

Application is at a rate such that the nutrient solution occupies up to 0.001 percent of the chamber volume at all times. So a cubic meter is 1000 liters so (1000 L *1000 ml/L) * (0.001/100) = 10 ml. That means at all times (with a chamber of one cubic meter) you need up to 10 ml of nutrient inside the chamber in an atomized state. This would mean with such a cahmber empty spray in 10 ml and see how long that remains in an atomized state. If say it appears 25% is gone in 1 minute that would mean every minute you need to spray 2.5 ml to maintain the 10 ml you desire in the chamber. This is without accounting for plant up take after the plants roots are in the chamber. The plants wil need an increased amount of nutrient solution, but not so much that you can actually see water droplets accumalating on the roots and dripping off (over saturation). Water droplets should also not form on the net pots. The atomixed nutrients should just be enough for the roots to feel damp.

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1. is the amount of mist in my video enough? Am I close, or am I orders of magnitude off?
2. Is separate nozzle system needed for first stages of growth,(i.e closer and pointed directly at root sites)? I don't understand nozzle to root site proximity and whether you should point nozzle at root site or rely on swirling mist/air current for proper saturation.

3. Is it ok if mist collects on walls/roof?

4. How do you calculate(what is the equation) for how many nozzles pump/line size will support?

Also, too bad Fatman7574 is extinct, does continuous, or long duration work(like 10 -30 sec)?

Fatman7574 said:

With a 50 (30 to 80) droplet size system you can actually run continously if using small enough nozzles. That is not possible with smaller or larger droplets sizes. With the 50 micron droplets the roots are exposed to air plus they recieve water and that can happen over a broad application range. Yes you can over saturate with 50 micron droplets by over sizing the nozzles are using to many nozzles. There are simple calculations to prevent that though. With small or large droplets you o\ver satuare then supply nothing, then you over saturate again then supply nothing. That is TAG. Or you simply constantly over saturate by fogging constantly.

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woah, finally got the datasheet from aeromist.com(they don't provide details besides "atomization") while the droplet size is, 43um, the flowrate is .02 GPH. Lol WHAT! Everything ive heard on here is closer to 1 -5 GPH.

I had some 1 GPH nozzles lying around. I didn't want to use them because they didn't have anti-drip, but I think they worked fine.

Does this mist amount look adequate? I will perhaps look into mounting them top down, but this seems much better.

0.02 gph is about 76ml/hr, they typed gph instead of gpm If you`re running 4 of these (miraculously low flowrate) nozzles on a 2sec/5min cycle, your 2gal accumulator should take 27 days to drop from 95psi to 70psi

Ya, their sales team is useless. Second set-up look ok? If you fix the typo, seems like the flow rates are the same on paper, I must do a test then. Regardless, the second set filled the chamber much better, and threw the mist much further.

Sorry about all the quotes from previous threads. I'm just trying to get all this stuff in one place, for me and the next noob.

Atomizer said:

The nozzles would be better directed horizontally between and below the netpots rather than pointing straight down. You`ll definitely need to handwater from the top until the roots are large enough to survive on just the smaller droplets that make it back to the top of the chamber. The bulk of the larger droplets will be lost on impact with the floor.

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Atomizer said:

The number one priority is to try and get a consistant moisture level in the rapid rooters as they`re the plants main source of water until they can use the mist. [...]

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Atomizer said:

He should be ok to leave the rooters intact as long as there isnt a huge amount of wet mist at the top of the chamber due to overmisting. The mist at the top usually consists of mostly small droplets that are relatively dry. The medium in the netpot is only needed in the early stages, once the roots have grown enough to be supported entirely by the mist you can let it dry out. Its better to undermist and handwater or drip from the top initially to keep the two zones (netpots/chamber) seperate. Misting the bejesus out of everything just to maintain the moisture level in the medium is counterproductive because it soaks the roots that have already cleared the netpots

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Atomizer said:

Sounds like the nozzles are mounted too high in the chamber, try to position them so the widest part of the cone pattern doesnt directly impact on the netpots.
Firing the nozzles upward between the flloor and lid generally gives them less space than firing along the length of the chamber. If the mist pattern doesnt get chance to form before it strikes the lid, you wont be get the full potential coverage from the nozzle. Its worth a go to see what its like, but my guess is it`ll take a lot more nozzles.

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So do the roots need support beyond what you mount them to the lid with? I thought you could just use a rubber-like conical plug(like rapid rooters?) with the roots protruding out of the bottom, hanging freely in the air.

The hago`s look to provide better coverage, i`d go with those..Thick neoprene discs or pool noodles cut into chunks will do the job.

Ya hago nozzles are made for combustion chambers, so they engineered the internals to increase exit velocity so can rapidly disperse/fill volume.

I will look into mounting them horizontally, half way up, but that may require too much tubing/pressure loss since I'm using 1/4 line and 100 psi tank. I didn't pay much attention in Fluid Dynamics class, because I was going into robotics. Perhaps, Version 2 I will try to get 3/8 and 125psi system then down adapt to 1/4 at nozzle.

I'd like to automate the hand watering you mention for early stage Clones. I'm thinking super low flow mister for each site very close, on separate solenoid, and doing like 10 second on/1min off, and then my microprocessor can just stop activating that solenoid after a week. Idk just a hypothesis, very uneducated.

I found netafim nozzles, but how can I mount them to my 1/4" flex tubing? I don't see any info that indicates it is possible. just a 1/2" pvc adapter.

http://www.greenhousemegastore.com/product/netafim-fogger-assembly/misting-heads

Everything is possible, you just have to think outside the box sometimes.
Netafim dont make a 1/4" pushfit mount for their nozzles but its very easy to make them yourself. What you need is some of these: (shop around for best prices, this was the first website i found with a pic) http://www.freedrinkingwater.com/parts/fittings/jg-whitepoly-male-connector.htm
The ones over here come in 2 varieties, the difference lies in the hole size in the threaded end of the fitting, one is larger than the other, 5.5mm and 8mm, you need the small hole type which ime are typically used on RO filter elements. Buy yourself a 15/64" straight hand reamer ($3-$5 off ebay) and ream the hole out with it to about 8mm deep (10 second job cos its only plastic).
You now have a threaded pushfit (bulkhead, if you buy a suitable nut) mount that will accept a netafim stem on one end and a 1/4" tube on the other. I`ve tested these to over 200psi and they dont leak or let go.

By reamer do you mean tap? When I think of reamer I think of this, we used them on Shuttle:

http://drillsandcutters.com/15-64-hss-straight-shank-straight-flute-chucking-reamer/?gclid=Cj0KEQjwkqKxBRCIrK_riNm13Z8BEiQAdzdVkBvbnkEU-llkV64z1T7XnWpOLSM70Ol3--UQfoUrlz0aAqoM8P8HAQ


Do you mean I'll ream the ID of the netafim tube, and then pressfit the quarter MPT adapter into it? No tapping?

A tap cuts threads, a reamer is used to enlarge a slightly undersized hole to ensure it ends up the right size and perfectly round, drill bits dont make perfectly round holes
Effectively, you just convert the hole in the threaded end of the adapter to accept the netafim stem (ie; the tube at the top of the adv in your nozzle link) as a push-fit. The 1/4" tube/pipe just pushes into the other end of the adapter as normal.
The netafims in your link are 7.5LPH, ideally you need 5`s. The adv ideally needs an orange pin, the ones in your link are purple which have a much lower opening pressure.

OH, so the OD of the netafim tube will fit in the ID of the 1/4" MPT side(making the threads irrelevant.) I couldn't judge the size in the photo, thought it was bigger, so didn't understand.

OK, back on the hunt I guess. Netafim's are scarce in USA. I have emailed HAGO Danfoss about what it would take to get some custom specs, because they mention to inquire about it. Probably would be too expensive/unit for just me, but just wanna see what they say. Ideally they could dial back the sauter mean to 21um like you say, and add the anti-drip feature to the lower pressure(60-100PSI) versions.

I videoed my spray but not sure how to view it frame by frame with a time-stamp to time the duration. I think I'm close enough just need the clones, so I can start, dial it in over next few months.

My next issue is that it gets to around 50F degrees in my garage. I have an insulated cabinet, so I bought a 50W heating pad to turn on under the root zone if it gets below, say 65F. I may have to build an insulated room around my cabinet and pump house air in there. I moved mid build, and couldn't fit it in the new house LOL!

The stems on the netafim adv`s and straight connectors have a slight taper to them, the stem is 9mm long, 5.88mm od at the top and 6.09mm od at the bottom. The reamer produces an accurate 5.95mm hole thats perfectly round. The threads can be useful for panel mounting nozzles, all you need is a 1/4 npt nylon/plastic nut or alternatively a 1/4 npt tap to cut a threaded hole in the panel.

What is the the proper bleach amount/interval to keep things clean throughout grow?
The USA EPA changed regulations in 2013-ish so that all bleach is now concentrated and mostly sodium hypochlorite.



This is what I was thinking i'd use: