Demon Genetics auto CBD aeroponic grow

My next grow is two seeds from Demon Genetics. One is a 1:1 CBD:THC auto, and the other is a 30:1 CBD:THC auto. Im interested in seeing how these two work out for pain relief.

I just finished a grow of some Dragon Tongue from @Sebring and Im really liking how well it does for my joint pain. I had to stop taking all NSAIDs due to kidney issues, and that really increased my joint pain. The Dragon Tongue RSO capsules I made are letting me get the best sleep Ive had in years, and making my daytime much more active with far less pain. Plus, Im not stoned during the day which makes for more productive time - couch lock is not a good way to get anything done!

Anyway, the system is still my air atomized aeroponic setup.

If you are interested in design details, check out my previous grow/build thread.

This is the earlier thread that goes over the initial design when I changed over from HPA.

Those are both long threads detailing my experiments in HPA and transitioning to AA aeroponics. Ive made a lot of mistakes along the way, but I think the system is moderately dialed in at this point, but Ive thought that before! :smiley:

Anyway, Im not going to be doing nearly as much posting of build details this time around. Its manly going to be a grow diary, so this should be a much shorter thread.

As always, anyone is free to ask questions, make off topic comments, make suggestions, or corrections, or what ever. Im not an ON TOPIC fanatic, but be warned - I have thread super powers, and IM not afraid to use them! :wink:

Ive made a few changes for this grow from the last one. They boil down to going back to my most successful nozzle location - at the bottom of the root chamber shooting UP.

On the last grow, I tried having three nozzles up at the top shooting across the chamber and that didnt work all that well. I ended up with large root balls at the top of the chamber, and a separate root mass on the bottom. The middle of the chamber was basically a dead zone. The upper root balls went straight for the nozzles and swallowed them by the end of the grow cycle.

This time, Im only running two nozzles, shooting UP from the bottom. Last time I did this, the roots also swallowed the nozzles. My solution to that problem is having the nozzles mounted to PVC pipes that extend up into the grow tent. I have it setup so I can raise or lower those pipes. Im going to start with them at the bottom, and hope I can raise them up enough as the grow progresses to keep them from being swallowed.

I also put each nozzle on its own timer and staggered the firing times. I think this will help maintain a more uniform mist density. The roots will tell me if this is working.
better or not

We will see if Im smarter than my roots this time around, but Im not willing to bet on it. So far, the roots have beet me to a pulp every single time! :smiley:


Some baby pics. They are droopy after transferring them from the mini-hempy dixie cups I started them in. They have been in the dixie cups for 6 days. These seeds are supposed to be ready for harvest in 63 days. We will see…


Well, Im not getting off to a great start this time, and Im not at all sure why.

As you can see in the pics above, the seedlings didnt look super happy. The leaves had started to tuck under and refused to perk up. This started before I transplanted them to the AA system, and it just got worse fast.

The roots looked ok to me when I took them out of the dixie cups - nice and white. I started them both at the same EC I always do = 0.5, and PH has stayed between 5.7 and about 6.1.

As of today, the 1:1 plant looks the worst while the 30:1 has finally started to perk up a bit.

The 1:1 also is showing some dark spots today.

The 30:1 looked almost as bad 2 days ago, but looks much better tonight.

Neither one seems to be getting taller and both have roots that are taking a long time to get started. Its probably not coincidental that the 30:1 has the best roots. The 1:1 roots are largely brownish and not throwing out new shoots much at all in comparison.

I decided to start a new 1:1 seed today. It will be almost 2 weeks behind the other one, but I can live with that I think.

I am concerned that both have super short internodal spacing. Im worried that I will get another one or two super stunted runts that will grow more mold.


I tossed out the 1:1. It was basically dead.

The 30:1 is looking better each day and the roots are finally taking off. There are even some fuzzy’s!

Im still worried about the super close nodal spacing, but will have to wait and see if it starts to stretch.


I sure wish @LemonadeJoe would get the viewer fixed so we can zoom in.


Day 19 - Time for an up-date.

The new 1:1 seedling turned 1 week old today, so I transferred it from the dixie cup to the AA system. For some reason, this one looks to be in better shape than the first time around. I dont see any specific reason why - its the same perlite in the same dixie cups, same water, same EC, same nutes, same lights, etc. I’ll take it though :slight_smile:

The 30:1 baby s doing much better. Its even starting to stretch a bit.

The roots are doing well. Im still running the nozzles on the heavy side, so not that many fuzzy hairs yet. I will start lowering the flow rate gradually in a few days. I want to let the new 1:1 get acclimated to the new environment a bit first.


Day 22 on the 30:1 and Day 10 for the 1:1

I discovered an unintended consequence of my building technique today. I ran out of 3/4" couplings when making the support pipes for the nozzles, so I used some T’s instead. These tubes go from the nozzles, which are at the bottom of the root chamber, and extend up into the grow space. At the top are other T’s so I can tell which way the nozzles are pointed. By using T’s in the root chamber and at the top of the pipes, I created a way for the air in the root chamber to get up into the grow tent.

A plus side of this is that my humidity has been running higher than it normally does. I had been sort of vaguely wondering why it was so much higher than normal, but didnt really worry about it or try to find out why.

The down side is that the mist in my root chamber was far less dense than I was expecting with significantly shorter hang times. I have been needing to run longer ON times and shorter OFF times than I was expecting. That I had been worrying about and racking my brain trying to figure out why. I re-did all my calculations several times trying to spot some error.

Finally, I realized what was going on and sealed up the pipes. My mist density and hang times are now much closer to what I was expecting to see with the new setup.

It wasnt just a matter of the humidity ‘leaking’ out of the root chamber into the tent. The exhaust fans I use keep the tent at a negative pressure - especially when #2 kicks on to keep the tent cool. The fans had been sucking my mist out and drawing a lot of extra fresh air into the root chamber - both of which would disperse the mist much faster than normal.

Im going to miss the extra humidity during early growth, but the roots need it more than the babies do.

Some pics from tonight. The 30:1 is doing well and starting to pick up some growth. The roots look good, but still dont have much in the way of fuzzy hairs. Im still running heavy on the flow rate for the new 1:1.

The 1:1 is looking ok too. Its not growing much yet, but the roots have just now begun to grow in the chamber. I expect to see better growth over the next few days.

Looking at the two, its amazing to me what 10 days difference looks like.

The 1:1

The 30:1

The roots are now on the floor of the chamber, so they are now over 30" long. I cant fit it all in one shot.


I forgot to post this - the 30:1 started showing sex at 21 days.



Day 24

The new 1:1 baby is looking weird, and twisted. Not quite the same way the first one did, but still not normal. The roots look great and are growing nicely, but the leaves sure look off to me.

The 30:1 is growing nicely now. I FIM’ed it last night. The roots are looking good too and are starting to develop some good fuzzy hairs.


Day 25

Im addicted to root porn and the wild things they can do - like ignore gravity and go off in any old direction.

I noticed this shoot yesterday, and tracked it back three days. Its heading for the ceiling of the root chamber - all by itself for some odd reason. That particular part of the chamber and ceiling isnt even in the direct path of the spray, so I have no idea why its going that direction. Normally, the roots go for the source of the water, but it doesnt look like thats the reason this time.

Starting three days ago:


Day 16 for the new 1:1 baby and it still looks like crap.
Day 28 for the 30:1 and it looks good.

The 1:1 leaves are just bizarre. They look like a combination of bad PH, nute deficiency, pest problems, RH problems, and almost anything else you can think of except nute burn. Whats really interesting about it is the roots look pretty good.

Im going to leave it in the system for at least a while longer. It costs me nothing to leave it in and Im curious to see what it does over time.

The 30:1 is responding to the training pretty well so far. I wish it would stretch out some more though. So far, Im able to do leaf tucking fairly well to help expose the new stems to more light. Im trying to avoid any pruning as much as I can.

The roots are looking good. I have been very slowly increasing the OFF times to lower the flow rate. Thats helping the fuzzies get going. So far Im liking the shape the roots are in as far as where they are spreading out. Last grow I had major issues because the roots went sideways and spread out way to much at the top. This time its going much better. I think thats due to having the nozzles down low shooting up.


Hey Larry,

I’ve been looking at getting in to some aeroponic experiments and came across your two threads. I’ve been going over them and may have missed it, but did you look at rotary/centrifugal atomizers at all for making your droplets?

There’s a paper that did some research on an aeroponic system with hydroponic backup in case of failure that did some tests with them to dial in drop size. ( It was a really interesting read. They were able to get a ~50 micron droplet size using a $10 motor with a $30 pump impeller. (Which to be fair is a 6" disk spinning at 3000 RPM and could be awkward to fit in to most root chambers)

If there’s a better spot for this or something let me know. I really appreciate your experiments and sharing them with the community.


Hello @TexanMD and welcome to OG!

This is fine for discussion of anything related to aeroponics, so feel free to join the discussion.

I read through that report early on in my aero research. They did some interesting stuff, but there were some design features they used that I didnt like much. I think making room for the disk is just the beginning of the design problems you will need to solve. In the end, I decided to go the HPA and now AAA route.

I think its telling to note that not one single system using disk atomization has ever been brought to market that I know of.

Every so often I come back to this idea though. Mainly because I happen to have a pile of small brushless motors and controllers available from my RC plane hobby.

Some of the design issues begin with having the motor and controller at the bottom of the root chamber. I cant see that working well for our plants. The roots will over whelm the motor system long before harvest. I couldn’t think of a good way to stop that.

The other main issue is the nutrient solution is always going to be salty - which leads to major corrosion issues for bearing, shafts, etc. Its not just going to be simple corrosion either. UNles you are very careful, you are going to be dealing with galvanic corrosion which can eat away metal at a phenomenal rate. Easily orders of magnitude faster than normal “rusting”.

It just looked like too much trouble to try to get a reliable system at any kind of reasonable price.

Plus there is the noise issue. Spinning disks make noise. The faster they go the louder they are. No way that system is going to work well if noise is an issue for you.

I decided that if I did try it, I would mount the motor at the top of the root chamber, in the center, and place plants around it. This would have the secondary advantage of not needing to blow the droplets around corners with fast moving air flow.

Droplets dont bounce, so they dont turn corners very well. It seemed like a better idea to throw the droplets out at the top of the chamber and let them fall naturally. Plus its fewer parts. You can also much more easily protect the motor from any water/mist. You would still need a stainless shaft, water proof bearings, etc, so not a simple design.

I think you also need a way to control the flow rate of the water feed independent of the droplet size.

I no longer think that having the disk at the top is a good idea though, or at least not a final solution. Aero roots have an amazing ability to grow towards the source of the water. They will seek it out and ignore gravity and logic to get to that source. If the disk is at the ceiling, the roots will grow along the ceiling until they get to the water or just grow out into open air for incredible distances with no support. If the disk is on the floor, its just that much easier for the roots to get to it.

Thats why Im now using a system where I can move the nozzles as the roots grow. So far, the roots have managed to grow over and into my nozzles every single time. It didnt matter if they were in the middle or top or bottom. The roots went straight for the nozzles. Im hoping I can move the nozzles enough to keep them away from the roots long enough to get through the grow. If I were making a bet, I would put my money on the roots though. They are undefeated! :smiley:

All of that said, its still a very intriguing idea. I doubt I will pursue it, but Id love to see someone else give it a go! I think aeroponics has tremendous potential, but I also think there has to be a better way to do the atomization. I just havent thought of one yet and havent seen any other ideas I like better than AAA - so far :slight_smile:

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Hey @TexanMD, I cant believe I forgot one of the key things that keeps me coming back to the disk atomization idea - the potential ability to maintain a constant mist density with NO wet dry variations.

Every HPA and AAA system that uses pumps/compressors, and spray nozzles has this wet/dry cycle to one degree or another. You turn a nozzle ON for a while, fill the chamber with mist, then turn it OFF and let things dry out as needed, then repeat.

I think the disk technique has the potential to generate a constant, unchanging level of mist in the chamber that regular nozzles do not. Unfortunately, they also have serious design challenges to over come.

If that could be done efficiently, quietly, and reliably, then it would be a big step up in aeroponics tech.

Fogponics with ultrasonic misters also have this potential to generate a constant level of mist, but they have a different set of issues. The biggest one being they generate mist that is too ‘dry’, and they fail way too often, are hard to clean, etc.

Between the two, I think disk has some advantages, but it needs more work. You have gotten me interested in this again, so I may mess with it over the summer when its too hot to grow for me.

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Day 30 minor up-date.

I was looking at the 30:1 tonight and thought I saw some weird dark scab looking things on the stems, so I tried out my new USB scope and a crude DIY holder. Its just a piece of 3/8" copper tube with a clamp on one end for the scope and the other end clamped to my light fixture.

Turns out this is just the purple from the Kush genetics - I hope! I also hope these early colors are a sign of things to come. One of the reasons I chose this strain was the colors :slight_smile:


@Larry3215 thanks for the detailed replies. I think the roots aggressive hunt for the disk is definitely one of the biggest things to overcome. I have a few ideas I’d like to try and see how they work. At least for the initial design and experiments I don’t actually need plants. If a chamber can’t be kept full of mist then I’ll have to move on to something else… probably AAA. I think I can get a motor+disk up and running for <$50 so I may try it out and see how it goes.

I need to finish your HPA thread, I just skimmed it, did you move to AAA for any particular reason? Was it basically that your pumps for HPA were starting to have issues and since you were in for the cost of pumps anyway, you decided to try AAA instead? It seems like overall AAA uses cheaper and more generic equipment and is less likely to have issues with clogs etc.

Looking forward to continuing to follow your grows. Hopefully I can do some experiments in a week or two. I need to get a PVC pipe hydro setup running in the next couple weeks though. I’m also going to put together some random electronics I have laying around to make a multi-channel timer that I can have <1 second resolution on each channel.

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AAA is more simple and much less problematic in the sense of maintaining, but AAA nozzles themselves might be pretty expensive. ebay is a friend though.

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Im going off memory here, but I believe that PDF said something like 3000 RPM was the minimum rpm that worked to get the droplet sizes in range. Are you planning to use the same humidifier disks, and RPM ranges? If you are not familiar with how to select a motor and controller to reach a specific RPM range, I can help. Ive been building custom RC aircraft of all sizes and power ranges for a few decades, so Im pretty familiar with motor/controller specs. :slight_smile:

One note - if you are planning to use those same disks, you might need to remove or modify the built-in propeller on the back side. Those disks are designed to forcefully blow the droplets out of a humidifier. You will not want any drastic air movement in your chamber while you are testing to see how much mist is produced. I suspect that for our purposes, the disk rotation alone, and the droplets flying away from the edge, will produce more than enough air movement to circulate the mist. Too much air flow inside the root chamber will just make the mist go away faster. When I say ‘too much’ Im really saying even very little air flow is still too much. Think slooow drift and you are in the ball park :slight_smile:

I changed over to AAA when I did the math on replacing my HPA pumps. However, as @heathen points out, that math did not include the spray nozzles. They are $$$ compared to HPA nozzles. If it wasnt for the nozzle cost, it would be cheaper to go AAA. The nozzles Im using now are cheaper than the ones Heathen is using, and they do work. I think maybe his work better though.

Other than the nozzles, the big difference between our two setups is he is doing pressure feed on the water side and Im doing siphon. My setup is cheaper because I dont need the extra regulator and solenoids, or a pressure vessel for the rez. His is easier to set up because I have to physically position a siphon tank near each nozzle and control the water level fairly precisely. His setup also has a wider range of adjustment as far as flow rates and droplet sizes.

Do let us know how you are doing on this, or better yet, start a thread here on OG, and keep us posted on your progress!

Im still 4 to 6 weeks from finishing this grow. I’ll probably start some tests of my own then. You have got me fired up about the potential for generating a constant mist environment with no wet/dry cycle. I might be willing to put up with some noise if that works. Not sure about my wife though!!


Day 33 minor up-date

These babies are supposed to be ready in 63 days from germination, so the 30:1 should be a little past the half way point. However, Its still not flowering, so we will see. Its also still pretty darn small.

The mutant still looks like a 3/4 dead mutant. The roots on the other hand, look great, are growing fast, are all the way to the bottom of the chamber, and developing fuzzys nicely. Im going to let it go to see what it does.

EDIT: Im glad I changed back to the nozzles on the bottom shooting up. The roots are developing in a much more manageable way. Im starting to see Atomizers inverted cone shape and they are not trying to swallow any nozzles - so far.


I am planning to use the same disc’s from the paper if possible. Probably the same motor too. I figure since they did detailed testing already for droplet size off that disc, if i use the same parts its less variables that are different if I’m getting drastically different results initially. I definitely think the propeller might have to be removed too, but i’m going to start out leaving it as is just to see if I can see any notable differences with and without it.

Also, those roots are looking great.