Adventures in Hydro #2 - LP Aero/NFT mash-up - or - switching to HPA?

Indoor Growing Hydroponics
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Some days I am just tooooo stupid to grow weed - or toooo stoned?

This morning I was messing with the nozzles, checking for clogging, mist patterns etc. As part of the testing, I put small Dixie cups over two of the nozzles while I check the third one.That way, I only have one mist stream at a time.

I bet you can guess what I did - or didnt do - when I was done… crap! I didnt look at the baby until tonight after more than12 hours of running on only a single nozzle. The leaves were all droopy and some of the roots are all shriveled up. There had been one small spot this morning that was just starting to show fuzzy hairs too!

arrrggghhhh!

On another note - I have been trying since I started this project, to think of other ways to generate a 50 micron mist in a root chamber that does not involve using hi-pressure or AA nozzles.

Over the last few days I have seen a few pics from guys doing DWC with roots that are super fuzzy and white - above the water line. Like this shot from @SquirtleSquad

https://overgrow.com/uploads/default/original/3X/f/8/f8f9e552d7ce9bd57f9f447de157b00dd738a345.jpg

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Obviously, those super fuzzy roots above the water are very happy, and they seem to be getting just about the perfect droplet size and amount.

So, the question is - could that be duplicated in a pure aero root chamber using some sort of water container and aeration of some sort?

I dont want to do dwc or have a huge tank of water sitting at the bottom of the chamber. I want pure aero roots. Not for any good reason - I just do :slight_smile: So, ideally, no water roots at all.

Im now trying to think of a good way to generate small bubbles using an air pump in some sort of circular container mounted near the top of the chamber. I dont like air stones, but I have not come up with a better way to generate small bubbles in large volumes in a small chamber.

@Northern_Loki was using a needle wheel pump to generate some super fine bubbles in his setup, but I have no first hand experience with those. I am worried they would generate too much flow through an open trough type container? No clue.

Anyway - if a good setup could be built - I picture this as being able to generate a constant supply of fine droplets coming down from the top of the chamber - no wet/dry cycles - all with no hi-pressure pumps, accumulators, solenoids, timers, or expensive AA nozzles.

Anyone have any ideas on this?

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Have you looked into “fogponics” yet, with an ultrasonic fogger in a rez constantly making fog? In my research (internet rabbit hole) i came across a few who managed.

I’m still waiting for the AA nozzle folks to get back to me on a 1-2gph 20-100u 10-30psi gravity feed nozzle.

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Yes, Ive looked into them a fair bit. The biggest problem is they produce droplets that are too small - sub 5 micron in most cases. That makes the fog too ‘dry’. The other big issue is that they build up a film on the surface of the oscillator that requires frequent cleaning and can be hard to get off. Kind of like the film that you get from boiling a pot dry. That and the cheaper ones dont last long when run 24/7.

Ive been wondering if they could be ‘tuned’ to produce larger droplets, but that still leaves the other issues of cleaning and life cycle.

Your comment about the HVLP sprayers got me to wondering if one of those could be adjusted/modified/McGyver’ed to put out smaller droplets? That still would not be really cheap, but maybe a step in the right direction. I need to look into how they are built.

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If they can suggest an inexpensive nozzle that does the job, that would be awesome.

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Aside from general stupidity, and forgetfulness, I can add failure to do simple math to my list of bad habits.

I may have found another part of the reason these nozzles are not doing as well as I hoped.

The Aeromist nozzles have a flow rate of 1.176 GPH or 1.23 ml/sec. I was running them at 0.4 seconds ON, for a flow volume of .492 ml per ON cycle.

The EcoLogic nozzles have a flow rate of .706 GPH, or .742 ml/sec, or about 60% of the flow rate. Some how I came up with 0.5 seconds having an equal flow volume, but thats way off. 0,5 x .742 = .371 ml/sec. I need at least 0.7 sec ON time to have the same flow per ON cycle. 0.7 sec ON = 0.519 ml/ cycle. A little higher, but better to be safe, so Im going up to 0.8 until the roots recover. If they dont start bouncing back soon, I may jump up to 1 second for a while.

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It occurred to me I can easily test the air stone droplet generator idea. I have an air pump, and tubing. I’ll pick up a couple of cheap air stones and try this out. I can use the same techniques I use to evaluate the mist in the chamber now. Just turn off the lights n the room, and use the cat toy or my small flashlight to illuminate the top of a container while its bubbling. If I rig this up in an enclosed space, so there are no air currents, I should be able to see if there are any hanging droplets.

I had another idea about this. Droplets that are in the right size range will float in the air easily. The air coming out of the air stone, should b e able to lift them up easily. However, larger, heavier droplets that are the wrong size, will tend to drop out sooner. It might be possible to “tune” the droplet size by placing the air stone in a container with tall sides that are adjustable in height. As you raise or lower the sides of the container, you should be able to control the size of the droplets - at least to some degree. The volume of air flowing would also be another way to tune the droplets sizes.

Maybe.

I should be able to test this this weekend.

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Yes, fairly high flow rate out of the pump. For those not familiar, a needlewheel pump is basically an aquarium pump with a modified impeller that looks like some sort of torture device. The impeller beats the fluid into submission instead of “pushing” it. It amount to an inefficient aquarium pump with a damaged impeller that’s also sucking in air. It’s primary purpose is to produce fine bubbles for protein skimmers. To do so, it needs to run at a fairly high RPM to finely “chop” up the air entering the pump all-the-while producing sufficient turbulence + flow to keep any larger bubbles from conglomerating. It’s purposefully designed to be a crappy pump.

With that said, out of the box one of these pumps likely has more flow than you’d need / want and would take some jiggering to balance things out. Some tuning for off-label use may be required. Off-topic, Larry and I saw some interesting dissolved O2 results (possibly going super-saturated by several percent) from the data on the system I have here. I’ll need to get back to testing / posting results at some point but the out-door season + life has had me busy on other things lately.

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Yeah, doesnt sound like that pump will do me much good. While I wait for some real air stones, I did a quick test with my fake/DIY air “plastic stones”. The results were very poor to middlin poor. There is some faint sign of micro droplets, but not much. Id guess 99% of the droplets are just big fat drops.

@SquirtleSquad said those roots grew in a bucket with just a waterfall - no stones at all, so my theory may be for crap. Im going to test anyway. If this works at all, it will be a dirt cheap, easy way to do true aero. Doesnt look good so far though.

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Another nozzle up-date. I received the replacement 70 psi springs from the Ecologic folks - and they still dont open :frowning:

So, I had an idea - I placed a thin nylon washer between the nozzle head and the ADV body - with no joy. When I tried two of them, and it worked! That reduced the compression on the spring enough so they start to drip at about 40 PSI, and work well at 60 PSI and above. This seems to have improved the spray pattern to some degree too - more uniform, but still not a perfect circle. I could only find one washer like that in my misc nuts/bolts/washers/screws drawer, so Im going to have to go to the hardware store and get some more.

The plant and roots started doing much better after I went up to 0.8 sec ON time. Early today I decided to go back down to 0.7 seconds. Tonight thats it looking good, so Im extending the OFF times in small steps. Im up to 70 seconds of OFF time, and finally starting to see hints of fuzzy hairs coming back.

I got some cheap air-tones soaking now. I’ll repeat the misting test later and report back. I have a new plan that may help…

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Oops - forgot the pics…

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I have messed with them enough to know how to work them, but not enough to understand exactly how they work. The pattern is adjustable by something like a proportioning valve, which can pass air to the holes that shape the spray.

The nozzle/needle combo dictate droplet size. Most that were used with the materials I was spraying are medium in the 225-250u range for spray stains, or medium-large at 400u or so for thicker lacquers as far as i remember.

I think it would be pretty easy to use one of those for this purpose. They are a dime a dozen at garage sales, pawn shops, etc.

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The question is, can one be easily modified to put out much smaller droplets in the 50 micro range?

Also, how loud are they? I only used one one time, and its been many years ago. I seem to remember it being kind of noisy, but Im not sure on that. It was in a shop that was already noisy.

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Well, my new plan actually works! By placing the air stones in a skinny tube, you can get a steady flow of droplets that look, to my eye, to be in the ball park size wise. I have 1/2" diameter stones, so I put one into a 10" long piece of 3/4" PCV pipe. It puts out a nice flow of droplets that can be seen a couple of inches above the top of the pipe.

That got me all excited, so I did a short flow test. Unfortunately, the results got me all UN-excited again. The flow rate is only 20 cc / hour from a single stone. Compare that to one of the nozzles Im using now at 2650 cc/hour.

So, I would need more than 100 of these to equal one nozzle as far as flow rate. This might work ok for a very small volume - like whats left at the top of a DWC bucket, but not a large HPA root chamber.

Im going to keep playing with this, but unless the flow rate can be increased drastically, its a dead end.

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Im going to have to quit doing math late at night. Especially after taking some of my med capsules!

This airstone idea may not be nearly as far off as I originally said.

My ecologic nozzles put out roughly 0.74 ml/second of ON time. But Im only running them at 0.8 seconds ON and then they are OFF for 60 seconds or so. That works out to about 48 seconds of ON time in each hour. That works out to a flow rate of only 35 ml/hour per nozzle.

This air stone looks like it can do 20 ml/hour, so not that far off at all. Two of them would equal one nozzle, so in theory, I would only need 6 stones to equal my 3 nozzles.

The huge advantage is the air stones would be putting out a steady, constant flow with no wet/dry cycle, so possibly you could get by with even less flow.

This is worth looking into further I think.

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I guess I should post a note over here too. Ive got the dam brown crap back on the roots. Been posting up-dates over here:

So far I have tried heavy duty pool shock treatments with no success. Next step is going to be some algaecide of some sort. Still looking into that.

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It’s been a while, so here is an up-date.

AAARRRGGGHHHH!!! I am feeling really frustrated the last several days.

This brown algae crap is driving me nuts. The heavy duty pool shock treatments (4ea one minute dunks in aprox 200PPM chlorine) did seem to at least slow it down, but they nearly killed the plant at the same time. On the plus side, the new root growth that started a few days later, seems to be – mostly - nice and white and rather vigorous. The roots have started growing fairly fast the last three days or so, but there are still brown sections in various places.

The problem is, I can’t tell the difference between roots that are air-pruning vs ones that have the brown crap growing on them. Actually, you can spot severely air-pruned roots because they turn dark brown and shrivel up, but roots in the early stages of air-pruning look just like they have the brown crap on them.

I’ve been playing with timing trying to eliminate, or at least reduce the large water droplets that accumulate. The main goal being to get some fuzzy hairs to start growing, but I have not been successful. The new roots are growing pretty fast, but I cant seem to get any fuzzies back.

The problem is in trying judge if the mist ratio is too low and causing air-pruning - or - is it the brown crap spreading?

Ive also been keeping up the pool shock at between 2 and 4 PPM. The goal there to help keep the algae from starting up again, but I cant tell is thats working or not. I am getting new brown sections, but is it the brown crap or air-pruning?

The question is – which of those three things is keeping me from getting fuzzy roots? Or, is it all of them together? I suspect its some combination of all three, but I dont know what to do about it.

I know the brown crap kills the hairs. I also know over misting, AND under-misting will keep the hairs from growing. The pool shock got rid of the few fuzzy hairs I had when the brown crap first showed up, so its bad for fuzzy hairs as well.

On the plus side, the plant looks pretty happy now that I stopped doseing it with toxic levels of chlorine. Also, the roots are growing again, and Im seeing some side branching, but its not nearly what I was hoping for.

Anyway, I don’t know what to do about this - short of starting over. The copper algaecide will be here tomorrow. Im hoping it will kill off the algae without killing the plant or wiping out the roots. Then maybe I can get back on track. We will find out soon…

Here are some current pics.

Oh, yeah, there is one other strange thing going on that I have not noticed in any of my other grows. Every evening around 8-9PM, the leaves start drooping. I have not been able to figure out why. The next morning, its all perked back up and looks great. Im running an 18/6 lights now, and they turn OFF at 1AM, and back on at 7AM. So this is occurring about 13-15 hours into the lights on time pretty regularly. There are no significant changes in PH, or temps occurring when this happens, so I have no clue why.

This plant also seems to be growing rather slowly. Its been just over 3 weeks since it sprouted, and it is only about 3" tall. It has two pairs of 3 finger leaves, one pair with five fingers, and one pair with seven fingers, plus a new set thats too small to tell yet.

Ive never grown C99 so I have no clue if this is normal or very slow growth.

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These are the roots from three days ago, and then today.

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Cindies are vigorous girls. They will show you as soon as this ugly brown stuff is defeated. Fingers crossed here - good vibes.

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I’ve been waiting for this update, thanks for posting!

Seems that there is way less brown stuff than in the last plant, right? So the shock, however detrimental to the development of the plant, did kill some brown stuff.

Just thought I’d mention - my algae in the perilite of the northern lights in coco that I fed from the infected rez went away. I did not do anything to it - I guess not wet enough.

But how can it grow in an entirely dark chamber ja beyond me. The fucker is photosynthetic, and really small, how does it get enough?

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Thanks! Thats good info. Im not killing this baby. She might die anyway, but Im not giving up :slight_smile:

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Perpaps they found something that eats them.
The only thing that got me rid of nasties at my DWC once and for all was bennies. So try I keep a healthy environment for them.

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