Roots are amazing, and they can be a real pain about growing where they are not wanted. Your long roots are growing about the same speed mine are - 6" per day more or less.
Its interesting to me that different parts of the roots can sense whats going on and react differently. In my case, those water droplets collect on the tips of some of them. That seems to make the root think its found a water source, so it keep growing longer, rather than getting fuzzy. The upper parts of the same root, or parts that dont collect those big fat drops, dont have sitting water, just the micro droplets, so they develop the fuzzy hairs instead of getting longer.
Not totally airtight, just the tops to prevent the light leaks and mist from escaping. The drains are all connected and open, and with the secondary/constant flow of water I was hoping that would draw in enough air. I also have large air stones with quite a bit of aeration in the res that was left over from the DWC and if needed I could drop a stone in each grow bed. (Not for bubbles, just for fresh air injection.)
I was thinking about this when I had heat problems in the grow beds and I read through Atomizers thoughts. While some of what he says makes sense, I am not a fan of his āyou have to do thisā methodology. NASA didnāt use permeable materials in their grow pyramids and plenty of people use the solid 4x4 fence posts with success, so there has to be something there.
Good thought, but for me the benefits of the solid containers outweigh the cons when I compare against fabric, so I will solve each issue as I come across them.
The long tap root problem is why I started looking into the root trellis idea. The spread of roots once they hit the hydroton in my last dual setup was incredible. But I also had to deal w/ the clay clogging the drain. Next time Iāll have the trellis to help fan things out, plus the material over my drain will prevent any root from getting too big and stretching all the way to the res. Still playing, I want as much root mass in the spray area as possible.
In my case, a blocked drain wont be a deal breaker. The excess water will just pass around the drain if its plugged up, and through the fabric bottom of the chamber, and still drip into the over flow pan. I wont have any puddles. The problem will be that the TDS monitor probe - inside the drain tubing - wont get enough water to register properly.
Speaking of tubing - I just discovered another interesting thing. When I added the new 200 micron filter, I placed it inside the space that encloses the root chamber. I left extra tubing on both sides of the filter so I could easily pull it out to change the element, flush it etc. I Noticed yesterday that the tubing does a pretty good dance when ever the solenoids fire. That extra motion has to be taking energy away from the water flow, and possibly adding some extra lag into my mist timing. So I decided to do a quick check. I took a short video of the spray and checked it in Movie Maker.
Turns out my 0.4 second timing is actually a full 0.5 seconds of mist coming out of the nozzles. All that excess tubing is adding an extra 0.1 sec to the ON time. I was wondering why the droplets were not getting smaller or fewer after I went down from 0.5 to 0.4.
Im going to have to see if I can take some of that extra out and fasten the tubing down so it cant move as much when the solenoids fire.
Ah interesting. I noticed the jump in the tubing as well, but never thought about that changing the timing. Most of my tubing is secured down using the c-clamps but not on the top. This will get solved when I migrate to the new nozzles that are hard-mounted on the side of the tub instead of in the lid though, Iāll definitely make sure I secure the tube now though. Good catch.
From the sounds of things, if your tubing was stiffer it would tighten up your timings and increase pressure at the nozzle, which is where you want it. If you are currently putting in pressure at the bottom end, the temporary expansion of the tubing might lower that to below spec and cause uneven spray patternsā¦
I had a look back through the thread to see. It was sad watching the plants get less and less healthy
Am I right in thinking you are using plastic piping to feed your solenoids?
Metal tubing would keep the pressure at the nozzle closer to the pressure feeding it.
Plastic tubing can act a bit like a rubber balloon would but less extreme, you feed pressure in at one end and it expands a bit and then releases the liquid over more time at a lower pressure at the other end. You may find that at the pressure you are using, 0.5 seconds is the fastest the piping will allow the pressure to be released. Either it would not get to the right pressure, or it would take that long to release it.
I donāt know the exact size of it, but something like brake line might be more suitable for your purposes. Can be bent to shape, designed for very high pressure etc.
@anon32470837 - Do you happen to have a link to the part you used to connect from the tubing to the nozzle? I know itās a sharkbite -> 10/24 connection, just canāt seem to find those locally so I need to buy online.
Which nozzles are you using? I posted links to the parts Im using from Aeromist earlier.
Im not using any adapters - I couldnt find any in-stock that went from 1/4" push fit to 10/24 - except for brass ones.
Im just screwing the 10/24 base of the nozzle swivel directly into the 1/4" tubing. You do have to take a couple of extra steps to do this so it will last. If you dont do this, they can get blasted out and it makes a mess
First, I wrap some Teflon plumbers tape around the 10/24 threads, but I dont do it the way youāre supposed to do it. I leave the threads near the tip exposed, and pile up an extra layer or two close to the swivel body. This is sort of a poor mans O-ring kind of thing. I want the base of the swivel to at least try to seal against the end of the tubing. Its added insurance for the next part.
I add these 1/4" hose clamps to the very end of the tubing, lock them down as tight as I can get it, then screw in the nozzles with the teflon tape. The clamp keeps the tubing from expanding when the nozzle threads in.
You are right about all that. I considered using metal tubing, but it would need to be stainless to be safe, and that pushed the budget just a bit. Im not sure if brake line tubing is stainless or not. It would also need to be the exact same outside diameter as my plastic tubing so it would seal into the push-fit connectors. All of that was enough to make me stick with the plastic.
However, Im using several things in the system to help mitigate those issues you mention - the goal being to create as crisp, and well defined spray cycle as possible. You are quite correct that varying pressures makes for sloppy mist generation. A slow build up, or a slow fall off in pressure will make the droplet sizes vary a lot. The initial burst of droplets and the final part of the cycle will all be larger than they should be if the pressure varies a bunch during the cycle.
First, the tubing, all valves, meters, regulator, etc, are fastened securely every where I can do so. The exception was the new filter. Thats now fixed.
The other main thing is to keep the solenoids as close to the nozzles as possible. That minimizes the run-on spray as the tubing de-presurizes. Im using one solenoid on each nozzle and the nozzles are only about 3" from the solenoid. I had to do that to keep the solenoids outside the root chamber for moisture issues.
The next biggie is using the anti-drip valves (ADVās) in the nozzles. They are supposed to stay closed until the pressure reaches a certain minimum level, based on the springs used. Then they close down and stop the water flow before the pressure drops to zero. They also prevent the nozzles, and tubing, between the solenoid and nozzle, from draining between ON cycles. That will all make for a much better defined and controlled mist cycle.
Thats the theory anyway. In practice, I think the ADVās that came with these nozzles are too week. These open at around 25-30 PSI, so Im going to order some stronger ones soon - 70 PSI or so.
Finally, using an accumulator tank, with a pressure reducing valve, keeps the pressure more uniform at the nozzles between cycling of the main pump. The pressure in the accumulator tank can drop from 135 PSI down to 110 PSI but the pressure reducer/regulator lets the nozzles see a constant 100 PSI the whole time. Well, close. The pressure reducer Im using is a little sloppy, but it was the only one that was all plastic and cheap. I set it to about 110 PSI on the gauge, and it drops to 100 when the solenoids kick on. Its close enough I think.
Now that the filter, and tubing are mounted properly, and 3 ft of excess tubing removed, I will have to wait a few hours before I can re-test the spray duration. There is still air trapped in the filter. That air makes for a very sloppy mist cycle. I can tell when there is air in the system because the needle on the pressure gauge moves down from 110 to 100 very very sloooowly. Once it is all purged, the needle responds very crisply.
@SuperiorBuds almost forgot - you can get those 1/4 nylon hose clamps at most hardware stores, auto parts or a marine store. My local HomeDepot didnt carry any that small, but Ace Hardware did.
I went ahead and ordered a full set of the Aeromist nozzles as well. I did the spray test w/ the old ones and while I didnāt mind the cone or droplet size, I had one clogged already so I figured Iāve give these a round.
Aha, gotcha. I believe I ended up finding the correct part I wanted, Iām just picking through the options now. Funny thing is I can get 10 cheap tees for ~$10 or I can get 10 better teeās w/ cheap nozzles for about the same cost. I might have to pick up a few before I find which tees I like the best.
While doing this research I also came across a cool little diagram that made me think of what @MicroDoser was just talking about.
Notice all of the SS parts available here? Hitting their site you can see everything ā but itās quite a bit more expensive for some items. More than anything Iām interested in a possible switch to SS lines so if nothing else this gives me a good idea of parts so I can search out cheaper alternatives.
I would imagine the mechanical anti-drip would be a bit āsloppyā as the pressure bleeds on the off cycle. One way around this (if it remains an issue and you want crisp cut-off) would be the use of pressure bypass solenoid that reroutes the pressurized fluid back into your reservoir. The solenoid is activated at the point you enter the āoffā cycle. But, that may lead to water hammer as a downside.
What size orifice did you decide on? Im using the .024 ones now, but I just ordered some .020 versions from a different supplier. I mainly wanted the 70PSI ADV springs. Im pretty sure the nozzles are the same from both companies, but just in case, I ordered the whole package - nozzles, springs, rubber balls, and anti-drip body.
Nice find! Those should work great for your nozzle setup. Id go black for more light blocking.
Im impressed at how cheap the SS parts are. I was sure they would be a lot more. I dont think Im going to switch
to SS any time soon. Im too cheap
I am sticking w/ my plastic John Guest fittings, but I think Iāll switch to 1/4" SS push-lock lines ā but only after the solenoid. I have far too much invested in the JG fittings and adapters to change the entire first half.
Almost forgot to respond to you on this. Ive been sidetracked trying to decide what to do about my browning roots, but more on that later.
Its been a while, but I did a good bit of reading on this exact subject. Using an additional solenoid the way you describe is something some people have tried, but they were doing it because their nozzles didnt have ADVās and they had a lot of tubing between the solenoids and nozzles.
The main reason to do either one is to stop run-on spraying, but its also important to have a crisp start to the mist cycle.
Youāre right about the ADVās being sloppy as far as when they open and close. None of the ones I have tried so far actually opened and closed at the pressures they said they did, and no two opened/closed at the same pressures the other ones did. Im sure its the springs they are using are just not strong enough or consistent enough.
Still, the ADVās have a big advantage as far as stopping run-on spray because they are located right inside the nozzle. There is no tubing, fittings, etc, full of water, between the ADV and the nozzle orifice. So, even though they are somewhat sloppy as far as exactly what pressure they open/close at, the response time is far better than a separate solenoid could ever have. Plus, there is no excess, pressurized tubing to contribute to run-on spraying at lower pressures.
The other disadvantage that an extra solenoid has is at the start of the spray cycle. When the primary solenoid first opens, it takes a certain amount of time for the pressure between the solenoid and nozzles to build up. That is exaggerated by extra tubing, fittings etc, between the nozzle and the solenoid. The ADV will not allow water to flow until it reaches a minimum pressure. That helps to give you a nice clean start to the mist cycle.
Without an ADV, the nozzles will start to flow at much lower pressures the instant the solenoid starts to open - even b efore its fully open. At that point, the pressure is still way too low, making for poor droplet formation.
So, without an ADV right in the nozzle, you will have low pressure ramping up at the beginning and ramping down at the end of the cycle.
Ive tried nozzles with no ADVās - the black plastic impingement nozzles from the NASA guys - and the mist pulse is very sloppy compared to the ones with ASVās. As long as the nozzles are very close to the solenoid and you have one solenoid per nozzle, its not too bad though. The solenoid itself acts like an ADV to a large degree, but the more tubing between the solenoid and nozzle, the worse it is.
The springs I have now are supposed to open at around 35 PSI, but its actually more like 25-30 at most and they dont shut off until the pressure is well under 20 PSI. Thats not good enough I dont think.
@SuperiorBuds - The new nozzles I ordered come with 70 PSI springs. I hope the parts are interchangeable with the ones from Aeromist. The nozzles look exactly the same, but I cant be sure. I decided to order the entire assembly just to be safe, but if the springs will fit either one, I will let you know. You may also want the stronger springs.
Im feeling more and more confident about the system over the last several days. I think Im getting a good handle on adjusting ON/OFF cycles, the plant is looking good, and things seem to be going pretty darn good as far as fuzzy roots.
There are a few bugs. Most are more a nuisance, but two are potentially worrying.
That timing issue I had above with the mist running for 0.5 seconds when the timer is set to 0.4 seconds turns out to be a solenoid issue. One of my solenoids is taking a lot longer to close than the others. About 0.2 seconds vrs 0.03 seconds for the others. A second one may also be slowing down, but its hard to tell. I cant reach it to get a good look unless I take the top off, and I dont want to do that yet. I have a spare on hand, so I will play with that when I remove this plant and start the C99 for the real grow. They may have some algae in them or are worn from the earlier over pressure I was running.
The other issue is the browning thats been showing up at the very top of the root mass. Its been pretty much unchanging for many days, but today it looks like its spreading a bit more today. I tried getting some close up pics with the USB scope, but I cant hold it steady enough when reaching through the tiny access hole I have in the root chamber wall. All I can tell is its brown. The rest of the roots are pure white and look great, so Im sure its NOT the nutes discoloring the roots.
The spread stopped when I did two things - added chlorine and sealed up the air leaks. Im fairly sure the air leaks started the problem, and now it looks like maybe the chlorine was holding it in check. Its been 4 days since I added any chlorine, and the last dose was a small one.
The rest of the roots look really good to me. There seems to be plenty of water getting to the top of the roots - there are droplets sitting on them and they feel wet to the touch. More importantly, fuzzies are growing almost everywhere i including right in with the brown spots. Those fuzzy hairs wont grow unless things are pretty darn close to ideal. Too wet or too dry and they go away pretty fast.
That leaves me thinking I have some root rot going on, so Im going to give them a hard dose of chlorine, and see what happens.
Here are some pics from today.
This the least blurry shot of the brown.
They look plenty wet. Its also interesting that where there is more brown, there are fewer or no fuzzy hairs.
One very interesting thing Ive seen the last coupe of days - the speed at which the longer roots are heading for the bottom of the chamber keeps slowing down as I increase the OFF times. Those fat drops that collect on the tips do seem to speed them heading down. When they dont have fat drops, they develop fuzzy hairs and go out to the sides more.
At the moment, I have the timer set at 0.4 seconds ON and 53 seconds OFF. Its actually closer to 0.5 seconds ON with the lag.
Im getting close to the end of the tests with this unknown seedling. Im going to go a few more days to see how the brown does , and to push the timing a bit more.
I have ordered two more SSRās so I can set up the second timer. The plan is for separate day and night intervals. Im not in a big hurry on that though. I dont think that will really be important until flower time or at the earliest - later in veg.
The next step is to start a new C99 seed in the system. I cant decide how I want to do it. I tried that trick with putting some fabric under the puck in the net pot and just dropping in the seed. That didnt work as well as I would like. The roots didnt want to grow through the fabric. They just wanted to stay on top - between the fabric and the puck - without growing down into the chamber.
Ive been trying to come up with a way to hold the seed in the neoprene puck, in the net pot, after it has sprouted.
It needs to hold the sprouted seed without damaging the new root, AND allow the seedling to push up into the tent above the puck, AND allow the new root to grow down easily, AND it needs to seal around the stem tightly enough so no air gets down inside the chamber to dry out the delicate new roots.
So far, I have not come up with anything I like. If anyone has any ideas, please post them?
If I dont come up with anything I like in the next few days, I will just start the seed in a small dixie cup and transplant it after a few days.
I accidentally found a new way to check hang times, and I think its kind of cool
I had noticed that when I was taking pics, the images were sometimes really foggy looking, and other times seemed perfectly clear. I just assumed the foggy images were because I happened to take a pic right after the nozzles fired.
Turns out, its a contrast issue. When the cam is pointed right at the roots, the cam dims down the image to compensate for them being so white. If the cam is pointed off to the side some, the fog shows up really well. You can see that in the video when I move the cam from one side of the chamber to the other.
I took a video of the entire time from just before the nozzles fired, to the next time they fired. Im at 0.5 ON and 53 off in this video. After seeing how thick the fog still was by the time the nozzles fired again, I increased the off time to 60 seconds. Iāll see how that is doing in the morning.
Iāll post the video as soon as it finishes up-loading to YouTube.
Good to know, Iāll keep an eye on your progress. My new parts will be here tomorrow but Iām headed out for a few days so I wonāt get any work done in the room until Monday at the earliest.
Iām pretty sure that the giant air-gap on my lid is what caused some of my problems last time, so itāll be interesting to see if that fixes it for you.
At least the browning was minimal and you seem to have caught it early enough. Then again my last run proved you can still pull some serious buds off a plant with crazy rot. I just wish I knew what I could have got had I not had any issues.
That makes a LOT of sense. I canāt wait to relocate my nozzles and try to eliminate the droplet build-up I was having.
I thought through this quite a bit myself. So far I havenāt found anything that works well for me ā normally Iād have hydroton to seat the taproot into, so this new setup had me confused. My clones come out of the aerocloner so theyāre already well started and easy to transplant, but Iāll have the same problem there w/ new seeds. I was going to try just keeping the seedling in the paper towel a bit longer, until thereās a 2-3" tap showing, then trying to move that into the puck. Iām afraid itāll have too much pressure on the taproot, though.
This is probably the safest method, but man it adds a lot of time to startup. If this ends up being the only thing that works reliability for us I can always start the seeds in the big soil room and clip clones from there.
Iām thinking I might try a small netpot w/ a little bit of hydroton and drop that in the system. Iāll have to see if the clay transfers enough water inwards for the seedling to feed from or not, though. It might actually need a higher spray rate until roots form, and Iām not sure if having the hydroton in there would cause issues later on or not. My trunk was the diameter of the entire 2" ring last time ā and I donāt want the hydroton stunting the growth.
