Here is a good example of what I talking about when I say things are better and worse at the same time. This is the dead zone over the last week. The left is about the time I stopped the copper, then a few days later, then today.
You can see that the brown is getting darker in the central region but at the same time the white fuzzies are popping out up top, and more new white fuzzies on the sides.
Well crap. I just tested the flow rate on the three nozzles I can still reach.
One of the existing nozzles is 2.26 LPH. The other existing one was 3.5 LPH. The new one I just installed is 10.9 LPH!!!
When I tested the three original nozzles, they averaged 2.68 LPH. with only a small spread - about 5% difference between them IIRC.
That was before I added the new 70 PSI springs and modded the ADVâs. That mod must have changed the flow rate on some of the nozzles significantly. Im sure it has to do with the spacers I added to reduce the spring pressure. The final pressure will vary depending on how tightly I screwed in the nozzle.
I just re-measured my actual flow from the rez and its right at 0.208 LPH, so the one I didnt test must be around 4 LPH.
Crap. Not sure what Im going to do. I also just realized that if I bang into the root ball where its fuzzy, the dent stays there - at least for a good long time.
Edit: Turns out a major part of the discrepancy in flow rate is leaks. Small leaks around the nozzles have a huge effect on the flow rate when its this low. Turns out, in all my fiddling with nozzle placement/angles, I have loosened the joints where the nozzles screw into the tubing. Need to fix those leaks and re-test. The spring tension does efect flow rate, but it can only lower it, not increase it. The nozzles with the hi flow rates were all leaking.
After much wasted time and a LOT Of cussing, I am throwing out the 70 PSI springs. I cant get them to be both consistent, and not leak. The trick I had to reduce the spring pressure is just to fiddly to work. If I adjust the pressure too tight, there is no flow or low flow. Even a slight reduction in pressure and they want to leak around my O-rings.
So Im back to the original 30 psi springs. The mist flow isnt as crisp, and well defined, but its far more uniform from one nozzle to the next - and no leaks. Even small drips from the connection points can double the flow rate.
I managed to lose two of the 35 psi springs, so now I need to order some more. I think I will order a couple more nozzles to have as spares while Im at it. I keep expecting these to plug up and need cleaning, but that doesnt seem to be a problem so far.
The fuzzy roots do NOT like being physically handled, dented or crushed. Once abused that way, they stay bent, crushed or what ever and dont spring right back. Im going to have to wait on new growth I guess to cover those areas I couldnt avoid touching while messing with nozzles. Im going to have to think hard about that - how to access the nozzles once the root ball gets toooooo big - before the next grow.
The three nozzles that now have the 35 PSI springs have the following flow rates.
2.8 LPH, 2.15 LPH and 2.66 LPH.
If Im doing the math right, the rear one is aprox 4 LPH, but I can see it is leaking, so its mist flow is probably close to the others. I will have to wait to fix it until I get more springs.
The plant seems pretty happy and is growing well. Im now 3 days into 12/12 and the plant is covering more than half the scrog screen. If this plant follows my other harvest rates, I could get somewhere between 10-16 oz from this one plant - maybe. If I can avoid beating the crap out of the roots 
I think my pride in the horizontal growth of the root ball may be a bit misplaced.
Ive been worried for some time about the way the under part of the root mass is always brown - especially in the center. Plus, the mat on the bottom is largely shielded by the root ball above - like an umbrella. Add in that the root ball is trying to smother the nozzles by growing too much to the sides.
I decided to re-read some of Atomizers old posts and one of them caught my eye.
Practical experience is the way to go, Keep the roots too wet and you`ll notice they will head straight for the floor and pile up⊠If you keep them too dry (or the droplet size is too small) they will spread horizontally at the top of the chamber and form a canopy. This usually results in the roots under the canopy blocking mist to the top of the canopy. The goal is to create an inverted cone of roots that gains in both girth and length. .
Looking at my roots from that perspective, It seem clear that I have made both mistakes.
At some early point, the roots were too wet and some of them went straight to the floor, but it looks like I over compensated and have been keeping them a tad too dry - causing the horizontal spread and the formation of my three sided âumbrellaâ root ball.
Part of the problem is that I forgot about that quote above and was thinking pure sideways growth was all good. Add in that I have also been obsessed with keeping the flow rates as low as possible and have gone too far in that direction. Plus - having nozzles that drip skews the numbers on flow rates which in turn leads to lower than ideal mist timing. I was thinking I was putting out say 5 liters/day when in fact the mist was only 2.6 litters/day with the rest useless drips.
I think I have been closer to ideal recently based on the look of the outer parts of the main lobes - the shoots are trending more down than sideways over the last several days.
BUT - I still do not have what I would consider an even distribution of mist. Part of the problem is the umbrella effect blocking parts of the mist flow, but the odd three cornered shape of the root ball also contributes to some areas being wetter than others.
At this point I dont know what would be best going forward. I dont see any good way to improve things much over what I have now other than to shift the timing toward the wet side and try to get the root ball to grow more down than sideways from here on out.
On another note - the brown may be starting to make a comeback. Im seeing reduced fuzzy hairs in a number of places. Some of that is probably my abuse of the roots, but not all of it.
The final parts I need to finish the RO filter system should be here soon. I am considering another copper blast right before I switch over to RO.
Oh - the heavy spray I did with the extra strong pool shock didnt seem to do anything other than kill off some fuzzy hairs where they got sprayed, so Im back to thinking the copper is the best way to treat the algae. The low dose shock did seem to keep it at bay for a while though, so once again, mixed signals make things difficult to pin down with certainty.
Ive been going back over old notes and generally reviewing things - trying to see if I have any OTHER major misunderstandings like the horizontal growing thing.
Part of that has been time playing with the spreadsheet I did to calculate flow rates. Some interesting things popped out when I took a close look at the numbers and how they change when you play with ON/OFF times, number of nozzles, and flow rates. You might find this interesting @SuperiorBuds.
Here is a screen shot.
Lines 2-5 are all the same ratio - 1/100. Line 6 is my current setting.
It looks like I was correct in my first assumption about the ratio of ON/OFF times determining the over all flow rate into the chamber. Timing values of 0.5/50 seconds and 0.6/60 seconds and 0.7/70 seconds, etc., all have the same exact flow rate of nutes into the chamber. For these Ecologic nozzles, those ratios all works out to 2.376 LPD. Changing the ON or OFF time raises or lowers the over all flow rate.
Atomizer has this to say about total daily throughput and the volume of each ON cycle into the chamber. In my spreadsheet, column H is total throughput in LPD. Column M is the volume of nutes injected on each cycle.
> 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.
Thats columns H and M in the spreadsheet - both in bold. Whats interesting to me is that I didnt really understand the relationship between these factors until I played with the spreadsheet.
So what he is saying is you set your ON time to âfill the chamber with mistâ and achieve the desired value for column M. His recommendation being somewhere between .02 - 0.04 ml/gallon in early growth and up to 0.06 ml/gallon of root chamber in late growth. I seem to be a little on the low side at 0.042 ml/gallon in my 46 gallon chamber.
For throughput, his numbers are 1.3 LPD early up to 2.65 LPD later. For where Im at in the grow cycle, I think Im a little on the hi side at 2.55, but not that far off.
So, Im hi on the over all flow rate (using more nutes than ideal) but low on filling the chamber - according to Atomizer anyway.
Of course, crunching numbers isnt quite the same as real life :D. It can get you in the ball park maybe, but watching the roots is the only way to tell for sure.
I get off on this kind of nerd stuff, so Im passing it on 
Edit: I just realized that Atomizers âTarget Daily Throughputâ has to be dependent on the size of the chamber. Hie 1.3 to 2.65 LPD numbers are based on a 26 gallon chamber. Mine is 46 gallons, so my comments above are not quite right.
Oh, here is the new version of the spreadsheet. Just change the extension from .PDF to .XLSX
flowrate2.PDF (13.4 KB)
I just realized that Atomizers âTarget Daily Throughputâ numbers I listed above has to be dependent on the size of the chamber. If you double the size of the chamber, the total flow should double as well.
His 1.3 to 2.65 LPD numbers are based on a 26 gallon chamber. Mine is 46 gallons, so my comments above are not quite right. For my chamber, I need to be going for 2.6 LPD on the low side and up to 5.3 LPD or so later in flower.
Ive been adjusting times and Im currently at 0.8/60 for about 3.15 LPD. Each cycle is injecting about .048 ml/gallon.
Those are both a little low based on his numbers but in the ball park. Im going to let the roots guide me from here on out.
@SuperiorBuds if you play with that spreadsheet, you will need to adjust the chamber volume in the formula for column M
Thanks @anon32470837 â thatâs great info to have on hand.
Looking back at my old pics it seems like I had the proper growth pattern. I can definitely see a âdead areaâ in the middle there where I wasnât getting enough mist, though.
I am getting close to mounting the nozzles in their new locations, so I can get some flow data then and we can crunch some additional numbers. I wasnât getting as many fuzzy roots near the end and I know I was off on my timings â the spreadsheet will hopefully help me get that worked out once and for all.
Though Iâm still not sure what I will do about the mist pattern. My plan was to go straight into the two sides of the tubs, allowing the swivels to stick out into the root zone for minor directional adjustments. Something like this:
This allows me to use a single solenoid per pair, connected via the SS tubing I picked up. If I angle them into the corners like I had before I will be fighting the hard lines (and it wonât be as clean of an install).
Maybe I will move them closer to the center and angle them towards the outside. Iâd hate to have to adjust the plan for a nozzle per side, but thatâd allow me to work on the spiral-flow type of thing you were going for.
You definitely had the inverted cone shape. It looks like you erred on the wet side while I was on the dry side.
Now that Ive increased the flow rates - trying to get the new root growth to trend down rather than sideways - Im seeing more of that same LPA root structure you have in that pic. The shoots that are getting more water are starting to put out those smaller side spurs. The frustrating thing is, Im getting new fuzzy shoots at the same time.
I think one of the major hurdles is going to be getting an even distribution of mist. Its clear I am NOT getting that. Some areas are too wet and some are too dry and some are just right.
One of the things I keep running up against is the dictum that you should not point the nozzles directly AT the roots.
Early in the growth cycle I pretty much had to point them right at the net pot or the roots starved. Now that the root ball is so huge, there really isnt any direction I can point the nozzles that wont at least have the side of the cone hitting the roots directly. If I didnt have the umbrella shape, that would not be nearly as big a problem though.
Lately I have been toying with the thought of having a set of nozzles up hi and another set down low that fire alternately or at different timing rates. Or maybe adding two more nozzles and firing pairs at different times. These timers Im using are cheap ($5.50ea), so adding more wont cost much. Of course, add on $7 for solenoids and $10 or so per nozzle, so the total isnt negligible.
OR - put them at the top shooting down OR at the top shooting sideways OR shooting at an angle somewhere�?
BUT - I dont know if or how much aqny of those changes would help
I think one thing to plan for sure is accessibility. Next go around I need to be able to get to them all easily. The one I have in the back is now buried in the roots. Increasing the flow rate didnt keep it from being swallowed whole.
I dont know what to tell you to try as far as placement. Im thinking my next round they will be some sort of modular unit that I can insert/remove from the top side of the chamber. The trick there is I dont want the water lines in the main grow space for heat reasons. If I can work it out, the nozzles would hang down from the top of the chamber with a 90deg ell so they could rotate in any direction, plus have the swivel for UP/down adjustments.
Imagine this as a sideview of the chamber. Ok, I changed my mind 5 times while I was doing this drawing, so consider this a vague idea
For your setup, would something like this be workable? If you did it this way, you could point the nozzles directly at the net pot early on, or make the mist swirl either way.
In other news, Ive stopped the latest copper treatment. The plant didnt seem to slow down as much this time and I also got new root growth - some fuzzy and some not. We will see if things take off again in a day or two.
One other thing I did this last time was hand spray some super concentrated copper directly on the roots. I concentrated it at the base of the net pot so the solution would soak down through the center of the root ball. I am assuming the mist doesnt penetrate into the center very well. I made the solution by using rez nute water and just adding extra copper to the hand sprayer.
I have no idea of that helped a whole bunch as far as killing brown crap, but it did cause me to discover something else that was interesting.
The TDS meter has been fairly even reading with my EC in the 1.0 to 1.2 range. The IN and OUT values are close. The runoff from the roots is close to the same EC as the feed water.
BUT - when I sprayed the concentrated solution, with the same starting EC as the feed water, it must have flushed some âstuffâ out of the center of the root ball. The IN/OUT reading had been close to 550 TDS, but shortly after doing the hand spray, the OUT reading jumped up to 930. That made me wonder, so I repeated it today with just plain nute water from the freshly filled rez. The IN and OUT both started out at 570 or so, but the OUT quickly rose to 840. After an hour or so, the readings were back to being close to each other.
This makes me think the interior of the root ball is building up something that I washed out with the heavy spray. I have read that roots have some sort of exudate or something. Im thinking thats what was washing out. Not sure what to make of that - if its good or bad?
In other other news, I got bored and made another GIF. This is the plant in the tent from about 10 DEC to 31 Dec, or about three weeks.
Almost forgot. I found an interesting PDF that has a lot of good info on droplet formation, sizes, and how they move.
I found this part especially interesting. It says a lot about âhang timesâ
442-032_pdf.pdf (725.8 KB)
I am amazed once again at how efficient HPA growing can be as far as nute use - at least potentially.
Its hard to do a completely fair comparison, but at about this same time in my last hydro grow, the plants were drinking around 1.5 gallons per day or a little more.
Right now, Im using less than one gallon per day - including the drips that dont do any good - and most of that is NOT getting on the roots. It ends up on the walls/floor/ceiling of the root chamber, or draining to bottom of the chamber in the collection tray. The daily runoff is still at least half of the amount Im putting out of the nozzles. So, the plants are only drinking maybe 1/2-3/4 gallon/day compared to 1.5 gallons per day with normal hydro.
If we could only come up with a more efficient, less wasteful way to create the mist environment, HPA would be truly killer.
Im already seeing new fuzzy growth after stopping the copper yesterday.
Also, even though the rear nozzle is completely buried in the roots by at least 2", I dont see any major problems with the roots in that area. The only issue is the top of the root ball is a bit drier than it was. The roots seem to be drinking faster everywhere, so Ive had to lower the off time to compensate.
My scrog screen is 3/4 full, so Im going to let the baby just go vertical from here on out. The C99 is supposed to be a short growing strain, so I should be fine.
Originally that was the plan but I changed in order to make it easier to use the stainless lines. Iâm headed downstate for a few days but when I get back I will get deeper into the nozzle placement. If I have to I will go back to the corner placement.
The other variable I still need to figure out is depth into the bed. I am thinking somewhere between 1/3 to 1/2 the distance from the top â but thatâs really just a guess based on what I did last time.
I really donât want to be relocating these later on so I will have to run quite a few tests before I figure out my final placement.
Thatâs why Iâm recirculating. I can go overboard w/ spray times and not worry about excessive use. Obviously the perfect system wouldnât need this, but I like the flexibility.
I also am thinking of plumbing in a few fence post runs so I can run my garden starts in the flower room. (Iâve already got a fodder system for the chickens running in the veg tent alongside my moms.) Multipurpose is always a good thing for me.
I am very curious to see if all this has any effect on yield or quality at the end.
Only the numbers will tell if all the fiddling has been worth it I guess.
Hope so.
I forgot which nozzles you are using this time? The SS nozzles seem to have roughly at 12"-15" throw depending on which ones. The Aeromist ones were longer throw, but larger 0.24 orifice. The newer Ecologic seem to be a bit shorter with the smaller 0.20 orifice. You might want to test the throw before you decide that for sure.
I agree with that 100%, but I think Im going to plan for some sort of options as far as placement - being able to raise/lower easily would sure be nice, and being able to rotate them is critical I think. Where you put them - and if they can stay in one place for the whole grow - will depend entirely on how your root ball grows. If it does the nice inverted cone again, thats relatively easy. In that case, a little higher in the chamber might be good. But if they spread out to the sides, or grow up vertically much, then you may have issues like Im having.
Im still thinking hard about setting up different hi/low âzonesâ with more nozzles on different timers.
What are the dimensions of your chambers going to be again?
Youâre right though, you need to do the testing first to see what options will be workable.
Yup 
The proof is/will be in the pudding - or the buds - as they say.
Although, in my case, I dont really care all that much about yields or taste. Even if I end up getting under 1 gm/watt, it will be plenty of meds to last me until the next grow. I dont care about taste because I dont eat or smoke - its just RSO into capsules for me. That said, faster finish times and greater yields would certainly be very very nice, and would help offset the costs.
My primary reason to do this was to get fuzzy roots, so I guess I have been more or less successful on that front. BUT - there is a lot of room for improvement.
With only a single plant, and a 3/4 full scrog screen, Im sure my yield per plant will go up a lot on this grow. However, the total yield for the tent, and gm/watt and gm/watt/sq ft/day may tell different stories. We will have to see.
At the moment, I find it hard to say that the end results are worth the extra effort, cost, etc. - unless you are into nerdy growing just for the nerdy growing sake - like I seem to be I find growing terribly boring for the most part, and all the HPA fiddle farting around keeps me interested
The plant and roots seem to be doing good to great at the moment. The plant is showing sex and growing well up top. The roots are growing still with lots of new white fuzzies, but as usual its not all good news. Other areas are nt doing as well.
This new growth spurt is causing me to adjust timing some more to increase the flow rates. Im now at 0.8/50 for a total flow rate of just over 1 gallon per day - which is a new hi. Im watching closely because several areas still seem on the dry side - mainly up on top of the root ball.
The new nozzle has helped to fill in the âdead zoneâ I had between the two front nozzles. I may raise it up higher so it sprays more on top of the root ball later today.
I got the RO system put together and tried it out last night.
Im sure glad I got the 400 GPD RO membrane because its only putting out about 160 GPD! Part of that Im sure is my water pressure. It was only 50 PSI at first, and after midnight it dropped to 40 PSI. Does the flow rate get better with these after a few days of use or is this the best I can hope for?
So, Im getting a little over 6 gallons/hour, so it will take roughly two to three hours to top of the rez depending on how low I let it get.
After cleaning and re-filling the rez with the RO water, I started by adding some calmag and 2 PPM pool shock. Then I phed down to about 4.5 or so. That took a lot less acid than before - maybe 40 ml or so. Then I started adding my diy PH up mix. I picked up some 92% Potassium Hydroxide flakes. Same stuff for home made soap. I mixed about 1/3 cup into 3/4 gallon of RO water. I didnt bother to calc the strength.
Anyway, it took maybe 40 ml of that to get back up to 5.6.
Then I added the mega crop to an EC of 1.1. That dropped the PH to 5.3-5.4 or so, and I added another 15-20 ml of the PH up to get it back to 5.5-5.6. That seemed to be holding PH pretty well, so I re-filled the accumulator tank.
Since Im doing drain to waste, I was hoping the PH would stay rock solid after that, but when I got up this morning it had risen to 5.8 in the rez.
Oddly, the PH in the holding tank had gone up to 6.0. I dont know why that would have happened. Normally, the PH is very stable once I pump the water into the accumulator tank, but it was just the opposite this time. The rez stayed more stable than the tank, but both went up.
Over all, I am happy with the new setup. The added time for a rez top off isnt that big a deal. I can start filling a bucket and just set a timer. Im hoping to get the PH thing dialed in better so the time savings of constant PH adjusting should help offset the fill times to some degree.
In the mean time, every thing else is progressing fairly well. The plant continues to grow well and the roots continue to grow - which is good and bad. The front dead zone is filling in very nicely with nice white fuzzy roots. However, the side lobes are now getting close tot he other tow nozzles.
Im having a hard time getting the perfect timing to get the fuzzies to grow DOWN instead of sideways.
Pics laterâŠ
Congrats.
Good call. This has been my experience as well. Youâd really need a booster to get the specified rates (if you look into the specs, most RO membranes require high pressures. The consumer versions are called high flow which usually have relaxed pressure requirements but still higher that the typically household). Temperature also has a huge effect. Other option is more membrane surface area (e.g. larger membrane).
Not that Iâm aware of. Factors: temperature + pressure (differential between waste and effluent) + âcleanlinessâ of the source into the membrane.
Waste flow rate will have an effect on how much âcrapâ will bond to the membrane (bad). You need enough waste flow to sweep the undesired particles from the membrane surface (e.g. the 1:1, 2:1, ratios). Otherwise, it will eventually stick in place reducing effulent flow further.
Get rid of the chlorine through the use of activated carbon pre-filtration. Small amounts of chlorine will degrade the membrane over time.
Thanks for filling me in on those details! The waste flow rate is one of the things I was unclear on. I dont have a âflow restricterâ as such. Im just put a cutoff valve on the outlet and adjusted it so the dirty flow was in the 1000 ml/minute range.
On-line, I couldnt find any hard and fast value for the waste flow rate for larger sized membranes. Some places advertise 800 ml/min as good for anything from 75 GPD up to 600 GPD systems, but other sites say you need 1200 ml/min for a 150 GPD system or larger. The MFG has zero info on their website, so I finally decided to go with 1000 ml/min ±âŠ
So, the PH thing isnt working at all the way I expected now that Im using RO water.
Last night I initially PHed down to 5.6, then filled the accumulator tank.
This morning the rez was up to 5.8 in the rez and 6.0 in the tank. So I dropped the PH back down to 5.6 for the whole system, and re-filled the tank.
This evening, the rez is back up to 6.1, and the tank is up to 6.4!
Keep in mind, there is NO re-circulation going on here. The rez and tank water have not touched a root. Its all drain to waste, so why is my PH raising faster than it did with the well water, and why is the tank water going up faster than the rez water?
With the well water, I understood that is was a dissolved C02 issue combined with clathlates(sp?) in the water.
Do I need to buffer more? I would have thought the second time I PHed down would have helped, but it seems to be worse.
